Update to 13.12 version number.
a memory leak occurs when use "support type" option

due to following reasons

void generateSupportGrid(SupportStorage& storage, OptimizedModel* om, int supportAngle, bool supportEverywhere, int supportXYDistance, int supportZDistance)
{
	storage.generated = false;
	if (supportAngle < 0)
		return;
	storage.generated = true;

	storage.gridOffset.X = om->vMin.x;
	...
	storage.grid = new vector<SupportPoint>[storage.gridWidth * storage.gridHeight];
    ...
Merge pull request #48 from mspark93/patch-1

a memory leak occurs when use "support type" option
Merge remote-tracking branch 'remotes/Ultimaker/master' into Extensio
Update clipper to 6.1.2, putting all Clipper depended code into the util/polygon.h
Merge branch 'master' of github.com:Ultimaker/CuraEngine
Add very simple test to check if the engine does not crash.
Fix the support with raft gap. https://github.com/daid/Cura/issues/622
Fix the odd skirt offset with support in some cases.
Remove inner holes from skirt. See https://github.com/daid/Cura/issues/685
Merge remote-tracking branch 'remotes/Ultimaker/master' into Extensio

Conflicts:
	gcodeExport.cpp
Fixed time calculation