Xedit toolbox autohiding. #tsk62

Clicking the top of the toolbox collapses the panel.
Hovering over the collapsed panel expand it and collapses again when
the mouse leave the toolbox.
Clicking again the top of the panel turn off the autohiding behaviuor.
Merge branch 'master' into feature/toolbox-autohide
Merge branch 'feature/tree-auto-hide' into feature/toolbox-autohide
Minor issue
Merge branch 'master' into feature/toolbox-autohide
Added icon for editor toolbox autohide.

Created a SASS file for kupustyles
Merge branch 'master' into feature/toolbox-autohide
Merge branch 'feature/toolbox-autohide'