main: Remove obsolete add_tearoffs properties
main: Remove obsolete rules-hint property usage
main: Remove debug option

Using G_MESSAGES_DEBUG=... or GStreamer's logging facilities yields
better results.
chapters: Remove "stock" icon usage
main: Fix spacing in version option
main: Move some app init code to totem_object_init()
main: When D-Bus activated, makes sure totem is a service

As per:
https://wiki.gnome.org/HowDoI/DBusApplicationLaunching
main: Add "remote-command" GAction

Which will be available on the bus for us to use.
main: Pass remote commands through D-Bus

Instead of expecting us to be called from the primary instance.
main: Remove unused totem_options_get_context()
main: Register GActions early

Register the GActions early, so that they are available even when
the main window isn't. This is necessary to make remote commands
available on D-Bus.
main: Make it possible to call app_init multiple times

This avoids us having to look inside the app's implementation to
know whether a window had been shown or not.
main: Re-implement command-line handling

Instead of implementing command-line parsing ourselves, use
the "handle-local-options" signal along with
g_application_add_main_option_entries() to parse command-line options.

Command-line options that work with a remote primary instance will be
passed over D-Bus with the "remote-command" action.
main: Move GApplication signal handlers to TotemObject

Instead of doing this inside the main() file.
main: Remove totem_options_process_early()
main: Remove unused totem_options_process_late() prototype

Declared but not actually implemented.