Allow triggers' names to be quoted identifiers

patch by Mikhail Stepura; reviewed by Sylvain Lebresne for CASSANDRA-7847
Merge branch 'cassandra-2.1.0' into cassandra-2.1
Allow triggers' names to be quoted identifiers

patch by Mikhail Stepura; reviewed by Sylvain Lebresne for CASSANDRA-7847
Merge branch 'cassandra-2.1' into trunk