Portability wrapper did not properly use the _defaultFetchMode when the method setFetchMode() was used on the Connection

- Fixed docblocks
- Removed return statements on void methods
- Cleaned up unused private / local variables
- Fixed license issues
- Removed SVN leftovers
- Fixed doctrine-project.org links
- Added line breaks before return statements

    Connection#insert(),  Connection#update() and Connection#delete(). Closes GH-271

DDC-217 - Refactor result caching to use a value object for all the important information which simplifies the code considerably and makes caching more powerful.

DDC-217 - Refactor result cache again to be much simpler, previous approach was too complicated and something like this needs longer testing. Now only caching the full result.

DDC-1337 - MySQL commits transaction on DROP TABLE, need DROP TEMPORARY TABLE. Added tests, looks like oracle commits transactions on CREATE TEMPORARY TABLE. I dont know how to fix it.