Database: added supplemental SqlsrvDriver

Driver is partially based on existing MsSqlDriver. The most significant change is reflection part.

Statement::normalizeRow() is changed to do right conversion of 'numeric' and 'smallmoney' values between 0 and 1. SQL Server returns e.g. '.5' string.

Statement::detectColumnTypes() is changed because SQL Server PDO driver returns 'native_type' and 'sqlsrv:decl_type' items in metadata, the first one contain always 'string'. It is a PDO driver feature mentioned in manual.

Driver has been developed and tested on Windows 7, PHP 5.3.8 and 5.4.13 with sqlsrv PDO driver 3.0.3421. As server has been used MS SQL Server 2012 (SP1) 11.0.3128.0 Express Edition.
tests: database tests adapted for sqlsrv PDO driver