Protocol changes for upcoming 0.27

This adds support for the protocol versions 76 and 77 that are used in the current mythtv/master.
76: http://code.mythtv.org/trac/changeset/d4dcff374e/mythtv
77: http://code.mythtv.org/trac/changeset/49dbed5be0/mythtv

This needs more testing before it can be merged.
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Also we have to check the database changes and adapt our code where necessary. (0.26 has scheme version 1307)
1308: http://code.mythtv.org/trac/changeset/563fc37cb01ce702806396ecf70657906e5d7125/mythtv (default value for channel.icon changed to '')
1309: http://code.mythtv.org/trac/changeset/a1f979393d4897d91b338581a14a2e245d76fa16/mythtv (change recording types)
1310: http://code.mythtv.org/trac/changeset/9497ba1b63a5a6a91b06dbb85beea37444ef3ccc/mythtv (change recording types)