unify & set window size

[balthazarneveu]

for jupyter notebook it would be good to be able to set the figure size. For Qt & matplotlib:

• "max" would be maximizing the window size

• "fullscreen" would allow to go fullscreen if possible

• setting (640,480) would allow setting the size in pixels

• [x] fix bug in current notebook implementation as the figure is huge

• [x] unify the interface

• [x] Qt backend has a F11 fullscreen key toggle.

---

size=None supported by default...

For pyQt & Mpl

• size="fullscreen", "full"

For pyQt

• size="maximized" , "max"

For Mpl & pyQt & nb

• size=(20, 8) for mpl & nb jupyter (inches)
• size=(600, 800) for pyqt (pixels)

For Mpl & pyQt & nb

• size=4 for mpl & nb jupyter (inches)
• size=(600, 800) for pyqt (pixels)