Merge branch 'feature/configure-email'

msmtp: fake "From" header only if is not set explicitly

msmtp: obscure a bit email in "From" header

People freak out seeing own email address in my "From".

Move definition of ask function into separate script in ~/bin

This way this functionality can be used from outside of shell, e.g in
mpop/msmtp config.

universe: add more programs needed for $dayjob

universe: psycopg2 and pyyaml python modules into the universe

These modules are useful for ad-hoc scripting for $dayjob, so it is convenient
to have them in the universe instead of using "nix-shell -p" all the time.

universe: add more needed tools

rc: re-define ask() function to use new method of accessing secrets

New script to create issues on github

New "issue-stdin" script is simple wrapper around gh(1) that accepts issue text
on stdin and automatically splits title and body in style of git-commit.

fasm-arch: add definitions from signal.h

rcrc: drop call for keychain(1)

Auto-generated key does not use keyphrase.

git-unignore ~/bin

It is better to have git track one-off scripts than to forget to commit some
valuable script.

New script: gist-buildlog

This script posts buildlog of the derivation on GitHub gist, making sure
that only one gist is created per derivation.

tig: add binding to put tag _ on selected commit

It is convenient to interactively put _ tag on commit to refer to it with other
git commands or scripts taking commit reference as paramter.

universe: remove explicit usage of nixFlakes

I don't use flakes now, but current Nix supports them out of box anyway.

tig: free more space for commit subject in main view

Use shorter representations for commit date and commit author to free more
space for commit subject.

neovim: use nvim-lspconfig plugin from nixpkgs, not pin

This pin got outdated and incompatible with nvim=0.6 too.

Fix name of variable holding "mod" haskell snippet

Due copy-paste error introduced in ccd5c23, s_data variable was overwritten
with "mod" snippet, resuling in "data" snippet not working.

In Lua, all undeclared variables get value "nil", which is, while is
undestandable from implementation point of view, quite annoying.

neovim: remove unneeded extra space in "data" haskell snippet

neovim: fix =/ mapping to properly save cursor location

Previously, it incorrectly used special purpose `] mark instead of general
purpose letter mark. Now it is using general purpose mark "z", which I don't
normally use.