[DBAL-42] Add support to reverse engineer Comments from MySQL, PostgreSQL and ORacle into Doctrine\DBAL\Schema\Column instances and added comment comparison into Comparator.

Fixed oracle integer/boolean type detection in OracleSchemaManager::_getPortableTableColumnDefinition()

Fix bug in Oracle Schema/Platform detection of DateTime vs DateTimeTz type and disable a logging test that breaky MySQL testsuite.

Added registerDoctrineMappingType() and getDoctrineMappingType() methods, converted DB2 platform and added some tests, made all platforms work for now

Support Sqlite

Migrated MySQL to Doctrine Type Map

Fixed nasty bug in testcase

Migrated Postgres to support Doctrine Mapping Types

Refactored Oracle Platform to support Doctrine Mapping Types

Refactored DB2 support for Doctrine Mapping Types a little bit

[2.0] DDC-312 -  Refactored View support of all platforms a little - Oracle now also supports the retrieval of the sql used to generate a view so that a common datastructure View is a viable option.

[2.0] DDC-302 - Drop convenience methods since their API is somewhat strange, have to think about something else. Dropped AbstractSchemaManager::listTableConstraints() support - since it only returns the names of all constraints, which are already returned much more nicely with listTableIndexes().

[2.0] DDC-214, DDC-303, DDC-304 - Fix several errors with Schema Inference from Database and Metadata and Comparisons, aswell as related bugs in DatabaseDriver. DDC-305 - Abstracted TRUNCATE command for all platforms.

[2.0] DDC-169 - Stripped case handling since its just a load of complex crap and doesn't solve any problem! Idea: just implement case-insensitivity in the comparator.

[2.0] DDC-169 - Added possibility to control which case mode schema assets are created with in SchemaManager

[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 - Converted introspection queries of all platforms to return Column, Sequence, Index, ForeignKey Schema Instances instead of arrays, heavily pimped Oracle support thereby.

[2.0] Fixed DDC-63 and DDC-106. Oracle tests for SchemaManager need further tweeking, marked as skipped for now.

[2.0] DDC-91 - Enhanced SchemaManager::listTableIndexes() considerably. Add primary keys to the index list, add a bool flag primary to each index, add an array of columns to each index. Moved a test to SchemaFunctionalTestCase to check that every database (Mysql, Pgsql, Sqlite, Oracle) returns exactly the same data from this function.

[2.0] DBAL cleanups (DDC-46). Proxy class improvements (DDC-19, DDC-39). Started new UPGRADE_TO document for upgrade instructions between advancing Doctrine 2 versions.

[2.0] Various necessary fixes and adjustments for oracle as well as fixes for better handling of temporal types. Closed #2452.

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reverting the reorganization done in 3455-3456 in order to make merging my experimental branch to trunk easier.

Preparation for new organization of code in to sub packages. Changed autoload() to work with new structure.