PHOENIX-1320 Update stats atomically

Conflicts:
	phoenix-core/src/main/java/org/apache/phoenix/coprocessor/UngroupedAggregateRegionObserver.java
	phoenix-core/src/main/java/org/apache/phoenix/query/ConnectionQueryServicesImpl.java
	phoenix-core/src/main/java/org/apache/phoenix/schema/stat/StatisticsCollector.java
	phoenix-core/src/main/java/org/apache/phoenix/schema/stat/StatisticsScanner.java
	phoenix-core/src/main/java/org/apache/phoenix/schema/stat/StatisticsUtils.java
Fix comparison for min time before doing an update stats and set small min in test
PHOENIX-1323 Use utility method to get HTableInterface for scans from coprocessor

Conflicts:
	phoenix-core/src/main/java/org/apache/phoenix/coprocessor/MetaDataEndpointImpl.java
PHOENIX-1315 Optimize query for Pig loader

Conflicts:
	phoenix-core/src/it/java/org/apache/phoenix/end2end/ReverseScanIT.java
	phoenix-core/src/it/java/org/apache/phoenix/hbase/index/balancer/IndexLoadBalancerIT.java
	phoenix-core/src/main/java/org/apache/phoenix/iterate/ConcatResultIterator.java
	phoenix-pig/src/main/java/org/apache/phoenix/pig/hadoop/PhoenixRecordReader.java
PHOENIX-1325 Pass in instead of calculate if we've crossed a region boundary in ScanRanges intersect methods

Conflicts:
	phoenix-core/src/main/java/org/apache/phoenix/cache/ServerCacheClient.java
PHOENIX-1257 Upserted data seen by SELECT in UPSERT SELECT execution (Lars Hofhansl)

Conflicts:
	phoenix-core/src/it/java/org/apache/phoenix/end2end/ReverseScanIT.java
	phoenix-core/src/main/java/org/apache/phoenix/execute/BaseQueryPlan.java
Increase memory and tweak test settings to get tests to pass on Mac