Add libx264-based h264 encoder plugin (#421110). Probably doesn't handle 'odd' widths...

Add libx264-based h264 encoder plugin (#421110). Probably doesn't handle 'odd' widths and heights correctly yet.

Original commit message from CVS:
Patch by: Michal Benes <michal.benes at itonis tv>
Patch by: Josef Zlomek <josef.zlomek at itonis tv>
* configure.ac:
* ext/Makefile.am:
* ext/x264/Makefile.am:
* ext/x264/gstx264enc.c: (gst_x264_enc_me_get_type),
(gst_x264_enc_analyse_get_type),
(gst_x264_enc_timestamp_queue_init),
(gst_x264_enc_timestamp_queue_free),
(gst_x264_enc_timestamp_queue_put),
(gst_x264_enc_timestamp_queue_get), (gst_x264_enc_header_buf),
(gst_x264_enc_set_src_caps), (gst_x264_enc_sink_set_caps),
(gst_x264_enc_base_init), (gst_x264_enc_class_init),
(gst_x264_enc_init), (gst_x264_enc_init_encoder),
(gst_x264_enc_close_encoder), (gst_x264_enc_dispose),
(gst_x264_enc_sink_event), (gst_x264_enc_chain),
(gst_x264_enc_encode_frame), (gst_x264_enc_change_state),
(gst_x264_enc_set_property), (gst_x264_enc_get_property),
(plugin_init):
* ext/x264/gstx264enc.h:
Add libx264-based h264 encoder plugin (#421110). Probably doesn't
handle 'odd' widths and heights correctly yet.