Copied current robotremoteserver.py from Robot Framework.

Contains fixes in RF 2.8.3 and 2.8.4:
- **kwarts support: http://code.google.com/p/robotframework/issues/detail?id=1596
- support for Mapping: http://code.google.com/p/robotframework/issues/detail?id=1597
- support for binary data: http://code.google.com/p/robotframework/issues/detail?id=1606
- use 127.0.0.1 instead of localhost: http://code.google.com/p/robotframework/issues/detail?id=1607

Also erases some enhancements done in this project earlier. Will add them back next.
Re-add changes done in this project from master.

Current status:
- We have all enhancements done in RF 2.8.3 and 2.8.4.
- We also have old enhancements done here.
- All tests pass (when run using current RF tip).

Next step is cleaning up tests and copying tests for new features from Robot.