Introducing blit.

Autoscale disabled.
Only working on one plot line.
Background restore working badly.
This branch ISN’T stable.
Blitting with class color. Respecting background.

New axes limit to help visualize without autoscale (useless with
blitting)
Blitting all the way.

Added option to change plot color or hide it even when stopped.
Reduced graph blitting to 1 second because now Rpi can handle it swell
Deleted autoscale. It should be implemented like an auto-follow.
Critical section in AcquisitionGUIs fix.

Main GUI behavior fixing.
Start/StopAll bug fixed for channel 3.

Graph sleeping relocated, OnRefreshAll fixed as well.
Merge pull request #1 from dmcelectrico/pre-alphas

Blit implemented as new optimized graph redrawing.