Made it a bit easier to add new fields and/or change their order
Replaced some unneccessary if-else-statements
Added font size and stroke width settings to ROI inspector
Fixed(?) a problem with too small figure text/comment boxes
Bugfix: Changing font size wasn't rendered on the fly
Fixed issue with invalid input for sizes (font size, width, etc.)
Removed wrong import statement
Merge pull request #2634 from dominikl/rebased/dev_5_0/roi_improvements

ROI improvements (rebased onto dev_5_0)