Add session file

Install it to /usr/share/gnome-session/ so GNOME's gnome-session
can find it.

data/meson.build

@@ -20,6 +20,26 @@ foreach desktop_file : desktop_files
   )
 endforeach
 
+sessions = [
+  'phosh.session',
+]
+foreach session: sessions
+  desktop = session + '.desktop'
+  i18n.merge_file(
+    session,
+    input: configure_file(
+      input: desktop + '.in.in',
+      output: desktop + '.in',
+      configuration: desktopconf
+    ),
+    output: session,
+    po_dir: '../po',
+    install: true,
+    install_dir: join_paths(sessiondir, 'sessions'),
+    type: 'desktop',
+  )
+endforeach
+
 runconf = configuration_data()
 runconf.set('bindir', bindir)
 runconf.set('libexecdir', libexecdir)

data/phosh.session.desktop.in.in

+[GNOME Session]
+Name=Phosh
+RequiredComponents=sm.puri.Phosh;org.gnome.SettingsDaemon.A11ySettings;org.gnome.SettingsDaemon.Clipboard;org.gnome.SettingsDaemon.Color;org.gnome.SettingsDaemon.Datetime;org.gnome.SettingsDaemon.Housekeeping;org.gnome.SettingsDaemon.Keyboard;org.gnome.SettingsDaemon.MediaKeys;org.gnome.SettingsDaemon.Mouse;org.gnome.SettingsDaemon.Power;org.gnome.SettingsDaemon.PrintNotifications;org.gnome.SettingsDaemon.Rfkill;org.gnome.SettingsDaemon.ScreensaverProxy;org.gnome.SettingsDaemon.Sharing;org.gnome.SettingsDaemon.Smartcard;org.gnome.SettingsDaemon.Sound;org.gnome.SettingsDaemon.Wacom;org.gnome.SettingsDaemon.XSettings;

meson.build

@@ -11,6 +11,7 @@ datadir = join_paths(prefix, get_option('datadir'))
 localedir = join_paths(prefix, get_option('localedir'))
 libexecdir = join_paths(prefix, get_option('libexecdir'))
 desktopdir = join_paths(datadir, 'applications')
+sessiondir = join_paths(datadir, 'gnome-session')
 pkgdatadir = join_paths(datadir, meson.project_name())
 
 config_h = configuration_data()

po/POTFILES.in

 data/sm.puri.Phosh.desktop.in.in
+data/phosh.session.desktop.in.in
 src/auth.c
 src/background.c
 src/batteryinfo.c