Break early when delete happens in outdated state

A panic could happen when multiple delete messages are sent one after
another without waiting until there are no messages left to be deleted:

	panic: runtime error: makeslice: len out of range

	goroutine 1 [running]:
	git.sr.ht/~sircmpwn/aerc/lib.(*MessageStore).Update(0xc000592e00, 0xa8fe60, 0xc0003340f0)
		/go/src/git.sr.ht/~sircmpwn/aerc/lib/msgstore.go:222 +0x5b8
	git.sr.ht/~sircmpwn/aerc/widgets.(*AccountView).onMessage(0xc0000a0460, 0xa8fe60, 0xc0003340f0)
		/go/src/git.sr.ht/~sircmpwn/aerc/widgets/account.go:251 +0x307
	git.sr.ht/~sircmpwn/aerc/widgets.(*AccountView).Tick(0xc0000a0460, 0xc0001496b0)
		/go/src/git.sr.ht/~sircmpwn/aerc/widgets/account.go:90 +0xa1
	git.sr.ht/~sircmpwn/aerc/widgets.(*Aerc).Tick(0xc0000a9f40, 0xc000020501)
		/go/src/git.sr.ht/~sircmpwn/aerc/widgets/aerc.go:123 +0x91
	main.main()
		/go/src/git.sr.ht/~sircmpwn/aerc/aerc.go:182 +0x5bf

The make that blows up is:

	uids := make([]uint32, len(store.uids)-len(msg.Uids))

This change simply checks whether the make is going to be valid before
starting to work on the actual delete. If there are more messages queued
to be deleted than what's left in the store, then we're obviously in an
inconsistent state, ask for an update and break.
Composer: fix EOF errors

PrepareHeaders generated a fresh message ID and Date header every time.
This instead generates those headers in advance.
Add custom sorting for folders

A new config options for accounts.conf (folders-sort) was added to
allow a user to choose which folders should be shown on top.
My use case was to avoid stepping into heavy, but rarely viewed folders
when cycling through other often accessed ones.

To test add this to your account.conf:

folders-sort  = INBOX,Sent,Archive

INBOX, Sent and Archive should then show at the top of your dirlist,
and all other folders should come next in alphabetical order.
remove garbage headers in reply message

Very important fix. Remove garbage from reply message headers. Till
now all Original fields were send in reply, which we do not want and could
lead to uncorrect email message.
failback to Content-Type filename when encoded Content-Disposition is used

Hi!
This patch will fix missing filename if it is RFC2231 encoded with charset
different then ASCII or UTF8. Example how it looks like in mail:

Content-Type: application/pdf;
 name="=?UTF-8?Q?Opis_przedmiotu_zam=c3=b3wienia_-_za=c5=82=c4=85cznik_nr_1?=
 =?UTF-8?Q?=2epdf?="
Content-Transfer-Encoding: base64
Content-Disposition: attachment;
 filename*0*=iso-8859-2''%4F%70%69%73%20%70%72%7A%65%64%6D%69%6F%74%75%20;
 filename*1*=%7A%61%6D%F3%77%69%65%6E%69%61%20%2D%20%7A%61%B3%B1%63%7A%6E;
 filename*2*=%69%6B%20%6E%72%20%31%2E%70%64%66

Yes, this should be forbidden :-). Anyway, best solotion in such cases
is to failback to Content-Type name. I am not sure if it is guaranted to
be there, but probably it will.

Leszek
decode(RFC 2047) imap headers to fix encoding in subject & filenames

Me again,
this time fixing encoding of subjects and attachments. It was problem in
IMAP backend. While other backends user MessageInfo() function which
generates MessageInfo decoded via go-message methodes, IMAP worker is
creating MessageInfo directly, so all non-utf8 subjects and filenames
were in raw form.

This patch fixes it. Not sure if we should care about errors (if
DecodeHeader fails it returns raw string back).

>From what I see, this should solve all encoding problem (tested only
IMAP). So, now I can focus on features. ;-)

Have a great weekend!
Leszek
use correct headers for message part

Hello guys,
on the hunt for bugs related to wrong encoding. This patch is fixing
reply to non-utf8 messages.

We were using global message headers instead of part specific. In
practice header were often something like:

multipart; boundry=...

where there should be:

text/plain; charset=...

Fixed also missing SubType.

Have great weekend!

Leszek
fix non-utf8 encoding in msgviewer

This patch should fix encoding problem with non-utf8 text/plain mime.
It is now correctly convert to utf8 before sending to pager. It will
also solve quoting such mails.

Leszek
fix make install directiories permissions

Hi everyone!
On my system I have strict umask set, so make install creates them
unreadable by non-root. This trivial fix ensures, that directories are
created as expected.

Leszek
Parse headers from template

This patch parses the processed template for headers and populates
matching header editors.
Those are then stripped from the template body before prepending the template
and remaining header fields to the composer content.

The main motivation for this is keeping receiver, sender and subject
lines in the template file and generating the message subject from the
date.
Initialize an empty message map in the message store on initialization

This addresses occasional crashes when a `MessageInfo` event reached the message
store before `DirectoryContents`, particularly on slower (imap) accounts.
Revert "Parse headers from template"

This reverts commit 31e3e9f56e0b8123f0238537112496b407055aef.
Fix crash when no message is selected

Pressing `Enter` on a view that has not yet loaded messages (e.g. at
startup) would return `nil` from `Selected()`. Accessing `msg.Uid` on a
`nil` reference crashes aerc.

This patch moves the `msg == nil` check before accessing `msg.Uid` thus
avoiding the crash.

To test this patch repeatedly press `Enter` on startup.
Parse headers from template

Parse the processed template for headers and populates matching header
editors accordingly.
Those are then stripped from the template body before prepending it
and remaining header fields to the composer content.

The motivation for this is keeping receiver, sender and subject
lines in the template file and generating the message subject with the
date functions.
Fix crash if there is no to address for %F
widgets/terminal: Reap more zombies

The editor and pager were not properly being reaped, causing resource
leakage whenever a user replies to a message.

Signed-off-by: Kevin Kuehler <keur@xcf.berkeley.edu>
Update version to 0.3.0
Install aerc-templates
Parse Reply-To header while parsing envelope
Allow fields in compose widget to be clicked

When the mouse is enabled, clicking on a header field switches focus to
that field (likewise for the terminal).
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