bit has special syntax for storing and retreiving so we'd need a
converter for that.
Storing 1 bit will result in one byte left padded on the disc so the
result of a query for boolean 0 will be 0x00 and for boolean 1 will be
0x80.
- Added drop/add primary key methods to QueryBuilder.php
- Added mysql specific dropPrimarykey method
- Added sqlite specific dropPrimarykey and addPrimaryKey methods
- Added uint testing for dropPrimarykey and addPrimaryKey methods
- Corrected postgresql column types, by adding length and precision