Creation of GCodeAnalyzer.py

Imported and translated from RepetierHost

First commit unfinished implementation
More implementation (still unusable)
G-codes and relevant M-codes implemented (check for tabs/spaces)
Indentation fixes, start pronterface modification
Bugfixes in the analyzer
Pause code (Ported from RepetierHost, untested)
Pause code working;
implemented the @pause gcode host command (and a small framework for host commands)
Indentation fixes, limit calculations
Host commands start with ;@
Merge branch 'core_mods' into experimental - implementation of pause
Merge branch 'experimental' of https://github.com/kliment/Printrun into experimental
Fix exception with join thread in print
Merge pull request #352 from fsantini/experimental

Recovery after pause