The current implementation uses the schema name as namespace name.
Some platforms don't support schema's, but a namespace name still needs to
be present. Added namespace name 'default' when there is no default schema
name.

default schema name is public for postgresql not default. Added debug
statements to test travis-CI.

Put the responsibility to give the default schema name from CreateSchemaSqlCollector to the Platforms (abstract, sqlserver, postgresql)

The namespace is used as name for the database schema. For SQL Server the default schema name is "dbo" and not "default".

- 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

DDC-1266 - Fixed bug where one sequence is dropped multiple times and extended that logic to tables and constraints

Fix bug in DropSchemaSQLCollector dropping tables before sequences which can cause constraint errors

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 - 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