ext/jp2k/: Add jp2kenc to jp2k plugin.

ext/jp2k/: Add jp2kenc to jp2k plugin.

Original commit message from CVS:
* ext/jp2k/Makefile.am:
* ext/jp2k/gstjasperdec.c: (gst_jasper_dec_class_init),
(gst_jasper_dec_change_state):
* ext/jp2k/gstjasperenc.c: (gst_jasper_enc_base_init),
(gst_jasper_enc_class_init), (gst_jasper_enc_init),
(gst_jasper_enc_reset), (gst_jasper_enc_set_src_caps),
(gst_jasper_enc_init_encoder), (gst_jasper_enc_sink_setcaps),
(gst_jasper_enc_get_data), (gst_jasper_enc_chain),
(gst_jasper_enc_set_property), (gst_jasper_enc_get_property),
(gst_jasper_enc_change_state):
* ext/jp2k/gstjasperenc.h:
* ext/jp2k/gstjp2k.c: (plugin_init):
Add jp2kenc to jp2k plugin.