[Free-cad-development] Merge request

[Jose L. C. <jlc...@gm...>]

New plot module (sanguinariojoe-plot) can be now integrated into master
branch.

It's not intrusive:

* Module checks for matplotlib before be loaded, and stop importing process
if matplotlib is not available printing warning at terminal. Then module is
not available anymore at workbenches list.
* Using autoconf or cmake matplotlib will seeked, but if not found a
warning will shown, plot module will not installed, and all process will
continue normally.
* Debian package only recommends matplotlib, but is not a hard dependency.

So module is only available if matplotlib is installed even if you use
Windows installer/Autoconf/CMake/Debian package (And I suppose that MAC OsX
is covered too), without old behaviour significant alteration.

Module behaviour is excellent (see tutorial)! And I'm actively documenting
it!

I'm waiting for merge before re-develope ship module (i will place a notice
on forum too).

Thanks!!!
Pepe