Bump patch version to 0.4.2

Fix autoload cookie typo in autocrypt-mu4e

Bind 'gnus-inhibit-mime-unbuttonizing' in 'autocrypt-gnus--get-part'

This prevents Gnus from inserting additional buttons when calling
'get-part'.

Use a custom constructor for 'autocrypt-peer'

Bump version to 0.4.1 for GNU ELPA

Assign copyright to the FSF

Relicense autocrypt under GPL-3

Recommend GNU ELPA as installation archive

Add auto-generated package.el files to .gitignore

Add a 'get-part' implementation for Gnus

Fold 'defalias' definitions for the MUA generic functions

Avoid usage of 'defsubst' where unnecessary

Remove setup example from the README

Add missing `-hook` suffix in readme hook name

Run M-x repunctuate-sentences on README

Remember to remove hook as modified in dd400cb

Prefer mu4e-view-rendered-hook if bound

Thanks to Thierry Volpiatto for notifying me to this change:
https://lists.sr.ht/~pkal/public-inbox/%3C875ye6bh0r.fsf%40posteo.net%3E

Adjust header formatting

Specifically the titles are now capitalised instead of uncased, and
the outline-minor-mode indentation is raised to 4 (one more than the
"Code" section).

Inline autocrypt-find-function

Fix custom type of autocrypt-process-header