Factor JredisPool to a common Pool interface
Add Lettuce connection pool for non-shared conns
Allow Lettuce connection pool for dedicated conns

DATAREDIS-201 

Inject LettucePool into LettuceConnectionFactory
to be used for a "dedicatedConnection". Dedicated 
connections are used only for blocking and tx ops
when a shared connection is used. If shareNativeConnection
is set to false, the dedicated conn will be
used for all ops.