#14 Extend the imput method on pythoncad Command

[Matteo Boscolo]

We need to extend the PythonCad entry with the following method

Different scale in x and y direction (vertical exaggeration).
Input on the command line in relative or absolute coordinates.

My Proposal is:
0,0 It's a absolute coords [Now works in this way for many commands]
0;0 It's a relative coords [Need to be implemented]
0>0 This is an angle (Distance>Angle) [Need to be Implemented]

To do this job, we need to create a function that accept a string and return a toule of coords with the absolute position.

[Gertwin]

I build in support for vertical exaggeration in the new draw functions.
The viewport maintains a different scale for x and y.

If I make a viewport member to set the vertical exaggeration I can multply the y-scale factor with it and do a redraw.
If the vertical exaggeration is different from default (1.0) than it must be visible on the statusbar.