Merge pull request #2424 from Benglin/RC0.7.2_Revit2015

Change GCRetain() and GCRelease() order
Do not use CurveLoop in RevitGeometryFromMirrorData method
Fix to handle longest lacing on empty arrays

It used to crash, it now doesn't execute the function

http://adsk-oss.myjetbrains.com/youtrack/issue/MAGN-4566
Merge pull request #2438 from junmendoza/RC0.7.2_Revit2015

Fix to handle longest lacing on empty arrays
Increase reference count for array elements