Fix Ctr-C and Ctr-D behavior.

Temp prompt

We replace the cmdloop function with a slightly modified version
to achieve standard unix shell behavior on keyboard interupts and EOF.

In order to do this, we consolidate handeling of printer status
with a Status class. The status class is updated by recvcb.

This has the side effect of simplifying the implementation of gettemp.

We also detect whether there is a heated build platform or not, and
don't display info about it if there isn't.

Prompt is now generated by a promptf() call for every cmdloop iteration.

updated gcoder

Conflicts:
	pronterface.py

added gcoder from another project. using gcoder to calculate dimensions and used filament

fixed measurement calculation for X and Y axis

Conflicts:

	pronsole.py

Add the GNU GPL text as the licese itselfs demands

GUI creation split