jdbcconfig - prevent stacktraces in tests

in JDBCGeoServerFacade due to null ResourceLoader
or missing LoggingInfo
jdbcconfig - enable spring transactions in tests
jdbcconfig - better db test support

- by default, run tests against h2
- add oracle and postgres profile to activate those tests
- support for getting connection info from system properties
- reuse jdbc datasource to speed up tests
jdbcconfig - fix oracle backend support

- support for differing Dialect
- remove 'AS' sugar constructs from generated sortby SQL
- fix various 'oid' sequence constructs (oracle uses nextval)
- add oracle views
- remove duplicate index creation causing problems with primary/foreign
  keys
- offset/limit support
- add truncate script to speed up oracle tests (instead of init/drop)
- initdrop tests to verify no failures
Merge pull request #631 from ischneider/jdbcconfig-oracle

Jdbcconfig oracle
Merge branch 'master' of git://github.com/geoserver/geoserver