QPID-5822: [Java Broker] Replace low level BDB/JDBC attributes in fovour of context variables from the model

* BDB attributes environmentConfiguration/replicatedEnvironmentConfiguration removed.  User can now specify
  context variables with the configuration keys that are understood by JE itself.
* JDBC attributes bigIntType/bytesForBlob/varBinaryType/blobType are now context variables with names begining qpid.jdbcstore.

git-svn-id: https://svn.apache.org/repos/asf/qpid/trunk@1603655 13f79535-47bb-0310-9956-ffa450edef68