re-add parameter columns to tracing session

patch by dbrosius reviewed by jbellis for cassandra-6942
Preserves CQL metadata when updating table from thrift

patch by mishail; reviewed by iamaleksey & slebresne for CASSANDRA-6831
Merge branch 'cassandra-1.2' into cassandra-2.0

Conflicts:
	src/java/org/apache/cassandra/thrift/CassandraServer.java
switch README to asciidoc extension
wip
formatting
Update debian packaging following README extension change
Document lack of order guarantees for BATCH statements

Patch by Tyler Hobbs, reviewed by Sylvain Lebresnse and Alex Popescu for
CASSANDRA-7123
Add Google Compute Engine snitch.

Patch by Brian Lynch, reviewed by brandonwilliams for CASSANDRA-7132
fix GCS test for 2.0
Patched version of Disruptor Thrift Server

patch by Mikhail Stepura; reviewed by Brandon Williams for CASSANDRA-6545
Cleanup selector's keys.

patch by Mikhail Stepura; reviewed by Brandon Williams for CASSANDRA-6546
Merge branch 'cassandra-1.2' into cassandra-2.0

Conflicts:
	src/java/org/apache/cassandra/thrift/CustomTHsHaServer.java
Add Google Compute Engine snitch

Patch by Brian Lynch, reviewed by brandonwilliams for CASSANDRA-7132
Merge branch 'cassandra-1.2' into cassandra-2.0
Fix writetime/ttl methods for static columns

patch by slebresne; reviewed by thobbs for CASSANDRA-7081
cleanup
Update system.peers correctly when relocating tokens.

Patch by brandonwilliams, reviewed by tjake for CASSANDRA-7126
Merge branch 'cassandra-1.2' into cassandra-2.0

Conflicts:
	CHANGES.txt
fix build