Replaced icons for new icons
Resized icon buttons
Added add-file and remove-file
improve editRectangle handling. Fixes #135
Merge pull request #136 from mgmax/develop

improve editRectangle handling. Fixes #135
Improve main window resizing. Fixes #133
Merge pull request #138 from mgmax/develop

Improve main window resizing. Fixes #133
merge branch 'develop' into feature-imodela