Rt

- PEP8 fixes
- update .travis.yml to update python interpreter list and some other small changes
- prefer format over % (PEP 3101)
- Add patch from https://gitlab.labs.nic.cz/labs/python-rt/issues/9
"Support CF search where special chars or spaces in CF names"
- Implement a fix for the issue suggested in
https://gitlab.labs.nic.cz/labs/python-rt/issues/10 (can't create ticket
with multi-line message)
- Implement fix for https://gitlab.labs.nic.cz/labs/python-rt/issues/7
"returned types inconsistent in get_ticket"
Add splitting for Cc and AdminCc

- added ability to steal, untake, and explicitly take tickets
- fixed create_ticket return value when provided an invalid custom field

- added ability to search all queues
- added RtError super class
- fixed compatibility issues with Python 2.6

- unit tests
- own exceptions
- added create_user, create_queue, edit_user, edit_queue methods
- added edit_link (replaces buggy edit_ticket_links)
- added get_attachments, get_short_history methods
- support merge_ticket in RT4
- custom query to search method
- strict binary handling with attachments

- added support for HTTP basic and digest authentication
- specification of errors to different exceptions

- fixed decoding of utf-8 only when needed
- updated search function to support various
lookup operators and sorting