Added ConfigManager to preserve some values. Fixes #221
Added exception checking into ConfigManager
Remade test_config_manager
gui: Fix some python2/3 incompatibilities
Fix some unicode encode/decode errors in PY2
Remade test_config_manager again
Merge pull request #235 from jkoncick/master

Added ConfigManager to preserve some values. Fixes #221. 

Also fixed some py2/3 and unicode encoding issues.