Revert "By default cassandra will no longer start without jna"

This reverts commit 68baaedd6f0adf4719f0c65296433d5f006c74c4.

Conflicts:
	CHANGES.txt
Fix NPE when streaming connection is not yet ready

patch by yukim; reviewed by Russell Spitzer for CASSANDRA-6210
Merge branch 'cassandra-2.0' into trunk
get ocd on log capitalization
bundle jna 4.0
patch by Lyuben Todorov; reviewed by jbellis for CASSANDRA-5872
Remove the assert from DataTracker.unsubscribe()
Merge branch 'cassandra-1.2' into cassandra-2.0
Merge branch 'cassandra-2.0' into trunk
Avoid rare duplicate read repair triggering

patch by Yang Wei; reviewed by Aleksey Yeschenko for CASSANDRA-6606
Merge branch 'cassandra-2.0' into trunk

Conflicts:
	src/java/org/apache/cassandra/service/ReadCallback.java
Fix ABSC reverse iterator's remove() method

patch by Mikhail Stepura; reviewed by Aleksey Yeschenko for
CASSANDRA-6629
Merge branch 'cassandra-1.2' into cassandra-2.0
Merge branch 'cassandra-2.0' into trunk

Conflicts:
	src/java/org/apache/cassandra/db/ArrayBackedSortedColumns.java
Fix paging discardFirst IllgalArgumentException

patch by slebresne; reviewed by thobbs for CASSANDRA-6555
Merge branch 'cassandra-2.0' into trunk
Cache a configurable amount of columns.
Updates after review
rename thrift config parameter