Add chapter on database portability, added section to data retrieval and manipulation on binding type handling and parameter lists.

Conflicts:
	reference/en/data-retrieval-and-manipulation.txt

[data-retrieval] fetchRow() has been renamed fetchAssoc() in the API. Changed the name in the documentation consequently.

Added Known Vendor Issues section into the DBAL manual, detailing PostgreSQL DateTime microseconds problem and the solution implemented in DBAL-33

Updating DBAL documentation, adding more text/thoroughness as well as splitting into multiple chapters since it will be separate documentation for DBAL.