rename gstccfilter.* -> gstcea708dec.*
complete changes for rename of ccfilter to successfully build and run
changes for pull request #3 review suggestions
additional changes for pull request review suggestions
fix a renaming error (cc_decoder_* => gst_cc_decoder_*)
Merge pull request #1 from cablelabs/text_track_refactor

Text track refactor
fix a renaming error (cc_decoder_* => gst_cc_decoder_*)
split ccdecoder into two parts: the initial user_data to dtvcc_packet decoder (ccdec), and the dtvcc_packet to webvtt decoder (cea708dec)
updates to get gst-launch test to work; still struggling with webkit
minor fixes to window definition, when to clear, and when to delete