Crop UI workflow improvements

[golemus]

crop is very frequently performed operation but its workflow is slow compared to other apps. Here are suggestions how to speed it up with minimal changes to codebase:


During presence of CROP toolbar:

Override following settings so that DOUBLE CLICK and ENTER are mapped to cropping picture:
settings - switching modes - double click
settings - switching modes - enter

Override following settings so that LEFT CLICK always executes crop box modification:
settings - mouse - left button - no modifier



Not as urgent but would improve workflow:
- make crop box side adjustment handles larger so that it is easier to aim/click them with mouse
- the region where tool changes to double sided arrow should be at least 2x but potentially 4x wider (or higher)
- some apps have also visual feedback where this drag region is with transparent green or such

[user0]

you can press Shift+X to crop