Discard UI() class and use plain functions

There is no real reason for using class there, it only adds extra
indirection and entangles function calls.

Note: Have to be careful where to put addon reference - it can't be at
module level (it confuses Python's garbage collector).
crunchy_json.py: Remove unused class _Info
Discard CrunchyJSON class and use plain functions

There is no real necessity for this class either.
Return utf8 encoded strings from _lang()
crunchy_json.py: Keep user data in args
crunchy_main.py: Call functions from crunchy_json directly
crunchy_main.py: Avoid using exec()
crunchy_main.py: Check success of loadShelf()
crunchy_json.py: Whitespace changes
Name variables more consistently
crunchy_main.py: Reduce verbosity in main by default
Close shelf before script exit
Merge pull request #13 from Reinis/fix_classes

Fix classes