[mythtv] Python requirement change

[Raymond Wagner]

The minimum requirements for the Python bindings has changed from 2.5 to 
2.6.  Additionally, experimental support for Python 2.7 is now added 
with the 'oursql' database module. (https://launchpad.net/oursql)

Currently, oursql support is disabled pending ticket #672059, and 
requires that the environmental variable 'ENABLE_OURSQL' be set to 
'true'.  If used without the patch on that ticket, database calls will 
fail against any database entries with empty DATE or DATETIME fields.

Also note that there are several changes in behavior of cursors that can 
no longer be relied upon.  When executing queries, MySQLdb would return 
the number of returned rows, or the last autoincrement ID.  The new 
oursql module does not return anything.  Autoincrement IDs can be found 
with the 'lastrowid' attribute.  Affected rows during a DELETE or UPDATE 
can be found through the 'rowcount' attribute.  Returned rows from a 
SELECT is no longer available, and can only be found by looping through 
all rows and counting the iterations.