Added JDBC event store

For usage sample see org.axonframework.eventstore.jdbc.JdbcEventStoreTest

Added support for configurable sql schema/sql statements by extracting separate class that creates PreparedStatements
Fixed connection leak, updated test to use pool - which reveals leak
Fixed more connection leaks
Minor documentation update
Merge branch 'jdbc-eventstore'
Merge remote-tracking branch 'origin/master'
ProcessingResult made protected

It was a private inner class, but declared as return value on a protected
method. This rendered the protected method unextensible.

Issue #AXON-223 Fixed
Added integration test to test EhCache JCache configuration