Feature changes
(shared_queue): more verbose trace logging
(main_win): use a thread to handle CoreMsgs instead of add_idle
(main): display error window if xi-editor crashes
(edit_view): add newline to end of the file if it doesn't terminate with one
(edit_view): only draw trailing spaces
(shared_queue): also use for sending stuff to xi
(gettext): build against system gettext
Bugfixes
(prefs_win): use pango::SCALE instead of hardcoding 1024
(edit_view): we don't ship the Inconsolata font anymore
(main): set config dir correctly
(prefs_win): fix choosing font size
(edit_view): fix scrollbar adjustment
(main_win): better CoreMsg trace msgs
(pref_storage): don't implement Clone for Config
(main): fix loading config
(main): don't load config twice
(linecache): fix linecount for wrapped lines
(ui): re-enable word wrapping, it's pretty complete now
(pref_storage): DO NOT clone Config to make sure it's consistent across different windows
(edit_view): send 'resize' to xi upon allocating a new size
(rpc): correctly handle measure_width
(meson): only validate appstream if appstream-util is recent enough