user settings UI layout improvements
reclaiming some unused space
unclutter user settings declarations
refactored section handling
split off settings label from internal settings name
split off settings page label from internal section name
removed settings file mixup
name convention and spelling fixes
added default values for display format settings
removed special value text from spin boxes (broken feature, not used anyway)
Removed all content from opencs.ini

Not needed since we already have reasonable default values within the code. Keeping the file to allow global modifications to these values.
added tooltip support to user settings UI
user settings cleanup
added advance 3D rendering user settings section
another layout correction
Merge branch 'settings'