Add unit-functional-tests into tarantool-python and, also:

    * Add Makefile for popular tasks
    * Remove unneeded code (from schema.py - field_defs, default_type
      and e.t.c)
    * Redo select request.
    * Make use of index_id, where specification allows it.
    * Make use of multi-part key in some requests.
    * Some bugfixes
    * Add new tests
    * Remove old tests
    * Pretty output for test-runner