When creating a cursor with result set type named_tuple
or dictionary, references were not decremented correctly.
For named tuples we don't use a static variable anymore, instead
of it will be created by PyStructSequence_NewType.
- added a thin python wrapper around mariadb module
- added constansts under mariadb.constants (CLIENT, CURSOR, INDICATOR)
- bench and test are now in testing subdirectory
- updated documentation
