shell: Move recent view to the App Menu

- Present the recent view only for empty new window.
- Add a "New Window" action to the App Menu to create
new empty windows.

https://bugzilla.gnome.org/show_bug.cgi?id=732289
shell: Fix the display comparison by name

GdkAppLaunchContext uses gdk_screen_make_display_name() when it has a
name to ruturn the display name, which appens the screen number. Use
g_str_has_prefix() instead of comparing the whole string.
shell: Pass NULL to g_app_info_launch_uris() when no uri is given
recent-view: Do not show/hide the recent view but open/destroy it

We can't switch back to recent view anymore, so there's no reason to
keep the recent view around. This fixes a crash when the document is
reloaded.