build: Switch to GtkSourceView 4

See merge request !15

build: Build with gcr4 by default

See merge request !14

desktop: Remove obsolete Bugzilla entries

See merge request !16

The X-GNOME-Bugzilla-* entries were for use by bug-buddy, a GNOME 2
technology that's been gone for over a decade. These entries are
obsolete and can be removed.

No API changes that affect us, other than the need to call init/finalize:

https://gnome.pages.gitlab.gnome.org/gtksourceview/gtksourceview5/porting-guide-3-to-4.html

Use -Dgcr3=true to build against gcr3 instead.

The gcr4 is going to replace gcr3, this change prepares it to do.
it also defaults to build with gcr4 for the same reason.

build: remove positional i18n.merge_file arguments

See merge request !13

Fixes build with meson 0.61

Updated deprecated g_memdup to g_memdup2

See merge request !12

[import] Remove deprecated GTimeVal

Closes #9

See merge request !11

If the imported file modification date is not valid we can use the
file name, which has been parsed and validated already.

GDateTime requires at least GLib 2.62

Using GDateTime instead to get the file modification datetime

Signed-off-by: Philip Withnall <pwithnall@endlessos.org>

main-window: Cast view & buffer objects

Closes #7

See merge request !9

The main window have an editable view and it correspondant
buffer using a GtkSourceView & GtkSourceBuffer. This patch cast the
objects into GtkTextView & GtkTextBuffer when it's required, removing
all the warnings generated by -Wincompatible-pointer-types compiler
flag.

Fixes: #7

main-window: Correctly convert Pango font description to CSS

Closes #4

See merge request !8

A Pango font description string is not actually CSS, as it doesn’t use
the same units. Correctly convert it using code from GTK.

Solution suggested by Rinat Ibragimov.

Signed-off-by: Philip Withnall <withnall@endlessm.com>

Fixes: #4

Signed-off-by: Philip Withnall <withnall@endlessm.com>

Signed-off-by: Philip Withnall <withnall@endlessm.com>

python3 module is deprecated since Meson 0.48.0

Meson supports this since 0.51 so we can now use this.

This also fixes incorrect parsing of versions like 1.13.1-unknown:

	Traceback (most recent call last):
	  File "/home/jtojnar/Projects/almanah/build-aux/gpg_check_version.py", line 39, in <module>
	    if check_version(gpg_version, accepted_version, is_gpgme):
	  File "/home/jtojnar/Projects/almanah/build-aux/gpg_check_version.py", line 19, in check_version
	    return int(gpg_major) == int(acc_major) and int(gpg_minor) >= int(acc_minor) and int(gpg_micro) >= int(acc_micro)
	ValueError: invalid literal for int() with base 10: '1-unknown'