it is best practice to implement retry logic for transactions that are aborted because of deadlocks or timeouts. this makes such method available inside the DBAL and also add detection for errors where retrying makes sense in the different database drivers

Features and changes:
* jsonb can be used with: options={"jsonb"=true}
* OVER is no longer reserved
* LATERAL is now reserved

add charset option for pdo_pgsql driver

- 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

[2.0] More general work on the SchemaManager and Platform classes. Making API more complete and adding sqlite and mysql test coverage.

First tests for basic collection implementation. First experimental use of closures (Currently commented out, because the svn server makes a syntax check against 5.2.x).