[2.0] Code cleanups. Preparations for DDC-193. Fixed DDC-399, type configuration remains global for now but the irritating instance methods on the Configuration have been removed. Use Type::addType et al. Added TODOs for naming standards.

[2.0] Refactored Doctrine\DBAL\Schema API a bit Table::createColumn() was inconsistent with all the other methods being add*

[2.0] DDC-169 - Changed AbstractPlatform and AbstractSchemaManager and children to accept Table, Index and ForeignKey instances for the respective create*() methods.

[2.0] DDC-169 - Finalized implementation of Schema diff algorithm, added diffs of sequences and foreign keys. Fixed several bugs and changed the API of the Schema objects.

[2.0] - DDC-169 - Began refactoring of DBAL code, introduced object notation for a database schema, including Tables, Indexes, Constraints, Sequences and Columns. Added a CreateSql Visitor which transforms a schema object graph into the required SQL statements to create it. Next: Replacing SchemaTool::getCreateSql() with new syntax...