added FilterList (allows to combine filters)
- fixed to_dict() in filter. did not work with ints (interval)
- added equals and repr
- check for bad operator
Minor bug fixing. Tests fixed.
Merge branch 'feature/pull12'

* feature/pull12:
  - fixed to_dict() in filter. did not work with ints (interval) - added equals and repr - check for bad operator
  added FilterList (allows to combine filters)
Fix EQUAL in filter's to_dict .
Wrapper now supports Py 2&3.
Imports in sub-modules are now relative.
Adapt pip to use private jsonobject repo until jsonobject 0.7.0 is released.
Symertical operator to __eq__ added.
Imports enhanced, some housekeeping done.