BUG: Remove warning message when opening Transforms module

Closes #3755

git-svn-id: http://svn.slicer.org/Slicer4/trunk@23463 3bd1e089-480b-0410-8dfb-8563597acbee
BUG: Fixed distorted sphere brush in editor paint tool

Out-of-plane dimension of the sphere brush was computed incorrectly. When a volume with anisotropic spacing was loaded then the bursh shape became ellipsoid.
(e.g., load the MRHead volume, set Z spacing to 10mm, draw in the sagittal view => enormous blobs appear on the axial and coronal slices).

The problem was that out-of-plane voxel size was computed incorrectly.

git-svn-id: http://svn.slicer.org/Slicer4/trunk@23464 3bd1e089-480b-0410-8dfb-8563597acbee
COMP: Do not package GitPython and PyGithub test directories. Fixes #3749

This commit reverts r23088 and now ensures that the test directories from
the GitPython and PyGithub python module install tree are removed. This
should fix the packaging issue caused by two long paths reported in
issue #3749 when install rules in "SlicerBlockInstallPython.cmake" where
executed.

To conveniently delete folders from the install tree, the CMake function
"ExternalProject_PythonModule_InstallTreeCleanup" has been introduced. Note
that it doesn't yet belong to the Slicer API and exists purely as an
implementation detail.

git-svn-id: http://svn.slicer.org/Slicer4/trunk@23465 3bd1e089-480b-0410-8dfb-8563597acbee