titan-core performance improvements
query.condition package improvements
Merge branch 'master' into fix-for-performance

Conflicts:
	titan-core/src/main/java/com/thinkaurelius/titan/graphdb/query/AbstractVertexCentricQueryBuilder.java
	titan-core/src/main/java/com/thinkaurelius/titan/graphdb/query/MultiVertexCentricQueryBuilder.java
	titan-core/src/main/java/com/thinkaurelius/titan/graphdb/query/VertexCentricQueryBuilder.java
	titan-core/src/main/java/com/thinkaurelius/titan/graphdb/query/condition/MultiCondition.java
	titan-core/src/main/java/com/thinkaurelius/titan/graphdb/transaction/StandardTitanTx.java
Fixes #417.
add LRU back to VertexCache and remove unnecessary boxing of longs
replace guava cache in LRUVertexCache with Solr based CLRUCache backed by NonBlockingHashMapLong
1) Added subsumption test to CacheVertex so that more restrictive queries can be answered from cache.
2) Renamed ImmutableLongObjectMap to RelationCache
3) Fixed ByteBufferUtilTest by using signum
Merge branch 'fix-for-performance' of github.com:thinkaurelius/titan into fix-for-performance
Rewriting of RelationCache to store properties of the relation directly (not in the map) and corresponding rewrite of EdgeSerializer where PropertiesHeader became redundant.
Changed LRUCache to use putIfAbsent to avoid concurrency issues.
enabled counters in LRUCache so its actually an LRUCache (i.e. keeps track of recency)
fix CLRUC.putIfAbsent to do maintenance only if new item was added + CLRUC.put is back.
fix LRUVertexCache.get on absent items
fix VertexLRUCache get to actually cache non-existing vertices
refactored sub-result set extraction into SliceQuery and added limit check.
Added StoreFeatures option supportsMultiQuery so that backends can indicate whether they can efficiently execute (i.e. bundle) multiQueries.
Add graph level configuration option parallel-backend-ops, which - when enabled - will create a thread pool that a backend transaction uses to parallelize multiQueries for backends that don't support them natively.
Added check in testGetSlices() for whether the store supports multiQuery
Fixed StoreFeatures for Cassandra.
removed HaselcastKCVS
changed test case to commit / restart transaction for close/open.