Documentation fixes

- 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

Fix foreign table name quotation in schema table and Sqlite platform

Introduced BC break with databases that switch from case-insensitive
to case-senstive handling when identifier quoting is enabled.

This reverts commit 11111bd7.

Quoting table name

[DBAL-374] Fix asset identfier quotation

Quoting table name to avoid errors with:
SELECT * FROM order;

Correcting reference to VarDateTimeType class.

[DDC-2470, DDC-2441] Use column name instead of alias to modify order by clause

VarDateTime is replaced by correct VarDateTimeType class.

Fix an instance of doubled words in the docs

Delete unnecessary "use PDO" statement

DBAL-522 - SQLParserUtils always throws exceptions on null bound params