* clutter.symbols: Update with the new public symbols
* clutter/clutter-script.h:
* clutter/clutter-script-private.h:
* clutter/clutter-script.c:
(parse_signals), (json_object_end),
(signal_info_free), (object_info_free): Parse the "signals"
member for GObjects.
(clutter_script_connect_signals),
(clutter_script_connect_signals_full): Add new API for autoconnecting
signal handlers using the UI definition files.
* tests/test-script.c:
* tests/test-script.json: Test signal autoconnection.