Switch liveRatio-related log messages to DEBUG

ninja-patch by Aleksey Yeschenko for CASSANDRA-7467
Handle KeyboardInterrupt properly in cqlsh

Patch by Jordon Pittier, reviewed by brandonwilliams for CASSANDRA-5481
Merge branch 'cassandra-1.2' into cassandra-2.0
Backport CASSANDRA-6747

patch by yukim; reviewed by krummas for CASSANDRA-7560
Adding SimpleDate and Time types