MySQL wrapped

New features were added to support the latest
version of dbdesigner. More operators were added
to the set_t class to manipulate a column of type
SET. The "is_null" method was added to Query
objects.

This version features better MySQL column type support:
bigint, enum, set, and unsigned integers. It uses the correct
type when returning mysql_insert_id(), and removes the use
of obsolete MySQL C API function calls.

This release adds minor bugfixes to support the latest version of
dbdesigner.

Improved error logging, code cleanup, and minor changes.

The old code was changed to use STL strings instead of char pointers.