[MOVED FROM BAD 10/28] ext/x264/: Use GQueue in stead of custom queue code.

[MOVED FROM BAD 10/28] ext/x264/: Use GQueue in stead of custom queue code.

Original commit message from CVS:
* ext/x264/Makefile.am:
* ext/x264/gstx264enc.c: (gst_x264_enc_set_src_caps),
(gst_x264_enc_sink_set_caps), (gst_x264_enc_init),
(gst_x264_enc_reset), (gst_x264_enc_finalize),
(gst_x264_enc_flush_frames), (gst_x264_enc_sink_event),
(gst_x264_enc_chain), (gst_x264_enc_encode_frame),
(gst_x264_enc_change_state), (gst_x264_enc_set_property):
* ext/x264/gstx264enc.h:
Use GQueue in stead of custom queue code.
Factorize flushing out encoder delayed frames.
Factorize initialization and state change reset.