Fix PSR2 rules : "As per PSR2, the static declaration should come after the visibility declaration."

Fixed inconsistent use of getSQLDeclaration method

- 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

Changed 'implements' by 'extends' because AbstractSchemaSynchronizer is a class not an interface (and Eclipse PDT shows a warning that say that "The type SQLAzureFederationsSynchronizer must implement the inherited method processSqlSafely, processSql" but those methods are already implemented on AbstractSchemaSynchronizer).