Make sstable directory picking blacklist-aware again

Patch by Aleksey Yeschenko; reviewed by Jonathan Ellis for
CASSANDRA-5193
Merge branch 'cassandra-1.2' into trunk
Log when a node is down longer than the hint window
Patch by Vijay, reviewed by Carl Yeksigian and jbellis for
CASSANDRA-4554
Merge branch 'cassandra-1.2' into trunk

Conflicts:
	test/unit/org/apache/cassandra/db/HintedHandOffTest.java
Deprecate but keep strings-as-blob support for now for compatibility sake
Merge branch 'cassandra-1.2' into trunk
Remove deprecated strings-as-blob for trunk
make local copies of compaction thresholds so they can't be changed out from under us mid-method
patch by jbellis for CASSANDRA-5214
Merge branch 'cassandra-1.2' into trunk
Correctly expire gossip states for edge cases.
Patch by yangwei, reviewed by brandonwilliams for CASSANDRA-5216
Merge branch 'cassandra-1.2' into trunk
Correctly expire gossip states for edge cases.
Patch by yangwei, reviewed by brandonwilliams for CASSANDRA-5216
Merge branch 'cassandra-1.2' into trunk

Conflicts:
	CHANGES.txt