Start MPL Process based background plotting
First working plot canvas with three object model.
Improve mpl processing api
Handle events in processes
Fix blocking in qthread checkit method due to receive w/o timeout
-Put multiprocessing stuff in extra module
-Connected classes implemented
First step of zoom working
First running version with MP plots on overview
Move 'draw' event skip from thread to process
Fix mouse position on plot widget
Toolbar stretch factor 0
align toolbar bottom
Change toolbar default sizes
Try toolbar style option
Set margins to 0