SSTableExport uses correct validator to create string representation of partition keys
patch by Alexey Zotov; reviewed by Benjamin Lerer for CASSANDRA-7498
merge from 2.1
Avoid IOOBE when building SyntaxError message snippet

Patch by Benjamin Lerer; review by Tyler Hobbs for CASSANDRA-7569
Merge branch 'cassandra-2.1' into trunk

Conflicts:
	src/java/org/apache/cassandra/cql3/ErrorCollector.java