add custom gnome session

closes #148

data/firstsetup.desktop

@@ -0,0 +1,9 @@
+[Desktop Entry]
+Name=FirstSetup
+Comment=This session provides a First Setup interface
+Exec=env GNOME_SHELL_SESSION_MODE=firstsetup gnome-session --builtin --session=firstsetup
+TryExec=gnome-shell
+Icon=
+Type=Application
+DesktopNames=vanilla:GNOME
+X-Ubuntu-Gettext-Domain=gnome-session-3.0

data/firstsetup.json

@@ -0,0 +1,9 @@
+{
+    "parentMode": "user",
+    "hasOverview": false,
+    "showWelcomeDialog": false,
+    "panel": { "left": [],
+               "center": ["dateMenu"],
+               "right": ["a11y", "keyboard", "quickSettings"]
+             }
+}

data/firstsetup.session

@@ -0,0 +1,3 @@
+[GNOME Session]
+Name=FirstSetup
+RequiredComponents=org.vanillaos.FirstSetup;org.gnome.Shell;org.gnome.SettingsDaemon.A11ySettings;org.gnome.SettingsDaemon.Color;org.gnome.SettingsDaemon.Datetime;org.gnome.SettingsDaemon.Housekeeping;org.gnome.SettingsDaemon.Keyboard;org.gnome.SettingsDaemon.MediaKeys;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;

data/meson.build

@@ -1,3 +1,18 @@
+install_data(
+    'firstsetup.desktop',
+    install_dir: join_paths(get_option('datadir'), 'xsessions')
+)
+
+install_data(
+    'firstsetup.json',
+    install_dir: join_paths(get_option('datadir'), 'gnome-shell', 'modes')
+)
+
+install_data(
+    'firstsetup.session',
+    install_dir: join_paths(get_option('datadir'), 'gnome-session', 'sessions')
+)
+
 desktop_file = i18n.merge_file(
   input: 'org.vanillaos.FirstSetup.desktop.in',
   output: 'org.vanillaos.FirstSetup.desktop',