Minor optimizations in GCode.pm
Moved vibration limit to its own G-code filter
Huge speed boost by reducing the number of method calls in GCode.pm
Move arc fitting code to its own post-processing filter and remove the built-in ExtrusionPath::Arc class
One minor optimization in GCode.pm
Refactor E code and keep track of per-extruder consumend filament
Removed MANIFEST since it's not used by Build.PL anymore
Merge branch 'master' into xsdata

Conflicts:
	lib/Slic3r/ExtrusionPath.pm
	lib/Slic3r/ExtrusionPath/Collection.pm
	lib/Slic3r/GCode.pm
	lib/Slic3r/Line.pm
	lib/Slic3r/Point.pm