Use Python 3 compatible Queue import
Use the new LZXY tile handling concept in the Qt 5 GUI

Also declare some class variables in __init__ to make Pylint happy. :)
Update bundled Urllib 3 to version 1.8

Fixes traceback on Python 3.4 (yeah, Sailfish really does
have Python 3.4 even before Fedora! :D) and should bring
also other fixes and improvements. And seems to be working fine so far.