Added a HConnectionFactory class, which creates HConnections. This is added to enable creating protected HConnections in phoenix.
Merge pull request #699 from kutschm/master

SpillableGroupBy - Dynamic SpillFile creation
Merge pull request #698 from Usha-Kuchibhotla/master

Added a HConnectionFactory class, which creates HConnections.
Use null tenantId to resolve base table and fetch from server if not in cache