PHOENIX-1328 Update ANALYZE syntax to collect stats on index tables and all tables (ramkrishna.s.vasudevan)

Conflicts:
	phoenix-core/src/main/antlr3/PhoenixSQL.g
	phoenix-core/src/main/java/org/apache/phoenix/schema/PTable.java
	phoenix-core/src/main/java/org/apache/phoenix/schema/PTableImpl.java
	phoenix-core/src/main/java/org/apache/phoenix/schema/stat/PTableStats.java
	phoenix-core/src/main/java/org/apache/phoenix/schema/stat/PTableStatsImpl.java
Move EMPTY_STATS impl to interface singleton