Added upgrade notice about BC break.
Cleanups

Changed DBALException::invalidPlatformSpecified() exception to be more detailed about what was given.

- includes extended default driver connection parameter handling
- minor refactoring

fixes #1183

- have forgot -> have forgotten
- larger or equal to 0 -> larger than or equal to 0

[DBAL-722] Introduce subclasses for runtime relevant exceptions (NotNull, DuplicateKey, ForeignKey Constraint Violation).

- 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

Fixed a PHP warning in DBALException::driverExceptionDuringQuery() when a parameter contains binary data.

[DBAL-178] Fixed an undescriptive error message and a problem when using custom types and their reverse engineering from the database. Allows Type#getMappedDatabaseTypes() to be implemented in custom types, mapping to vendor database types during reverse engineering.