thrift api updated for CASSANDRA-66

[Jonathan Ellis <jb...@gmail.com>]

Another heads up -- the thrift API has been updated.  Method
parameters have not changed but CassandraException was replaced with
NotFoundException (for when a specific column value that does not
exist is requested) and InvalidRequestException (for invalid requests
such as bogus table or CF).

Also, as proposed on the mailing list a few days ago, methods
returning a list will return an empty list if no matching data is
present rather than throwing an exception.

Internal errors during a client api method will now always be logged.
(This was mostly the case before, but not always.)

Finally, I added insert_blocking taking the same arguments as insert,
and added a workaround for the thrift bug that has been generating
Python code with syntax errors.

-Jonathan