Fix typo
Disallow incompatible type change in CQL3

patch by slebresne; reviewed by iamaleksey for CASSANDRA-5882
Versions for 1.2.9 release
Allow disabling SlabAllocator
patch by jbellis; reviewed by jasobrown for CASSANDRA-5935
Make user-defined compactionJMX blocking
patch by jbellis; reviewed by Michael Harris for CASSANDRA-4952
merge from 1.2