Add meson build system (#1)

Initial meson build system support. We do not create .desktop file yet, but we need an option to open media files from GUI first anyway.

build-aux/meson/postinstall.py

@@ -0,0 +1,22 @@
+#!/usr/bin/env python3
+
+from os import environ, path
+from subprocess import call
+
+prefix = environ.get('MESON_INSTALL_PREFIX', '/usr/local')
+datadir = path.join(prefix, 'share')
+destdir = environ.get('DESTDIR', '')
+
+# Package managers set this so we don't need to run
+#if not destdir:
+    # NO CLAPPER ICON YET
+    #print('Updating icon cache...')
+    #call(['gtk-update-icon-cache', '-qtf', path.join(datadir, 'icons', 'hicolor')])
+
+    # NO CLAPPER DESKTOP FILES YET
+    #print('Updating desktop database...')
+    #call(['update-desktop-database', '-q', path.join(datadir, 'applications')])
+
+    # NO CLAPPER SCHEMAS YET
+    #print('Compiling GSettings schemas...')
+    #call(['glib-compile-schemas', path.join(datadir, 'glib-2.0', 'schemas')])