Porting to meson

[gpoo]

This branch add supports for Meson build system. This PR is on top of #54, so it is only one commit (cca0335)

One can test it as:

$ meson configure _build
$ cd _build
$ ninja

To create the tarball (inside the build directory):

$ ninja dist

I usually build with a prefix that is in my user account. But that is up to every user. It works fine on
Gnome builder once one sets up the following variables: XDG_DATA_DIRS and PYTHONPATH.

[mikelolasagasti]

I can't execute after ninja install, I get the following error:

Traceback (most recent call last):
  File "/usr/local/bin/revelation", line 79, in do_activate
    self.__init_ui()
  File "/usr/local/bin/revelation", line 418, in __init_ui
    pixbufs = [ self.items.load_icon("info.olasagasti.revelation", size, 0) for size in ( 128, 48, 32, 24, 16) ]
  File "/usr/local/bin/revelation", line 418, in <listcomp>
    pixbufs = [ self.items.load_icon("info.olasagasti.revelation", size, 0) for size in ( 128, 48, 32, 24, 16) ]
gi.repository.GLib.GError: gtk-icon-theme-error-quark: Icon 'info.olasagasti.revelation' not present in theme Adwaita (0)

Which is strange, as icon files are being installed in same /usr/local/share/icons/hicolor/128x128/apps with autotools and meson.

Then, translation files have changed from revelation.mo to info.olasagasti.revelation.mo. I don't know if this will work with defined gettext domain.

[mikelolasagasti]

Works after running manually:

$ sudo gtk-update-icon-cache -tf /usr/local/share/icons/hicolor/

In meson_post_install.py icon_cache_dir is set to:

icon_cache_dir = os.path.join(datadir, 'revelation', 'icons', 'hicolor')

That would be:

/usr/local/share/revelation/icons/hicolor

App's custom icons are installed in that path, but logo icon is installed in /usr/local/share/icons/hicolor. I think this, having icons installed in different paths depending what they're for, is compliance with icon specification. Unless this is wrong or not a best practice, adding another gtk-update-icon-cache for the second path would be enough.

[mikelolasagasti]

Works great now! Much faster than with autotools!