List of features to be implemented (not in any particular order)
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-- map tools to stylus buttons (maybe: btn click on toolbar item affects
- the corresponding tool; tool switching cleaner than for eraser)
-- move selection to another page by drag-drop
- (should apply to vertspacer when origin moves to another page,
- but in the up direction only do so when all the stuff fits on prev page)
- (SEE ALSO FEATURE REQUEST 1472482 and reply to it - optional behavior too?)
- lasso selection tool
- prefs file, save prefs
- flatten (incl undo/redo...) - enabled only if nlayers>1
- more pen/highlighter shapes (chisel)
- convert to/from Jarnal format; to/from MS Journal format???
- recalibration upon screen resize / compensation for miscalibration
+- find a better behavior for vertical space tool across page boundaries ?
+- document the file format
+