Upgrade Thrift to 0.9.1

patch by Carl Yeksigian and Jake Farrell; reviewed by Aleksey Yeschenko
for CASSANDRA-5923
Merge branch 'cassandra-2.0' into trunk

Conflicts:
	src/java/org/apache/cassandra/service/StorageService.java
	tools/stress/src/org/apache/cassandra/stress/Session.java
	tools/stress/src/org/apache/cassandra/stress/StressStatistics.java