fix bad merge
Rework node replacement.
Patch by brandonwilliams, reviewed by Tyle Hobbs for CASSANDRA-5916
Merge branch 'cassandra-1.2' into cassandra-2.0

Conflicts:
	NEWS.txt
	src/java/org/apache/cassandra/gms/Gossiper.java
	src/java/org/apache/cassandra/service/StorageService.java