[DBAL-220] Add support for Index flags and implement support for SQL Server CLUSTERED/NONCLUSTERED and MySQL FULLTEXT.

DBAL-54 - Fix sequence drop executed before tables, however sequences mostly depend on tables. Also clean up several test-failures on MSSQL tests and  Oracle Index detection.

DBAL-50 - Fix another follow-up bug, Index column names are not being sanitized to lower-case, which will make comparisons fail that shouldnt.

DBAL-50 - Explicitly add an index for each foreign key added to a Schema\Table instance. Removed code to FixSchema based on foreign keys, since assumptions now dont apply anymore. Refactored algorithms to check for duplicate or potential overrule indexes into Schema\Index classes, added tests and unified Table API handling these conflicts

[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 - Introduced handling of schema / database case-sensitivity differences and to allow compability between different platforms.

[2.0] DDC-169 - Changed AbstractPlatform and AbstractSchemaManager Constraint API to accept Constraint interface, which is implemented by indexes and foreign keys.

[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 - Fixed another regression in refactored SchemaTool, began porting of eZ Components Database Schema Comparator, SchemaDiff and TableDiff.

[2.0] - DDC-169 - Added DropSchemaSql Visitor - Refactored Visitor package a bit, however its still not very appealing to have that much use statements cluttered in the code

[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...