Make Face request synchronous

[definability]

Fitters are hard to read and support. Need to implement synchronous Face image getter, e. g.

new_face_image = self.get_face(face)

Possible solutions:

• ~AsyncIO may help this, but code will be incompatible with Python <3.5;~
• ~Another solution is to use events;~
• Implement synchronous Face drawing for fitting only, because it blocks keyboard/mouse input.