BUG: Manually download distribute required for SimpleITK

Download distribute version required by SimpleITK's build directory to
be automatically detected by distribute_setup.py. The distribute
download from pipy has moved to a https URL. SSL is not yet supported by
Slicer's version of python. So we moved the download to midas and
manually get it.

From: Bradley Lowekamp <blowekamp@mail.nih.gov>

git-svn-id: http://svn.slicer.org/Slicer4/trunk@22164 3bd1e089-480b-0410-8dfb-8563597acbee
ENH: Updating SimpelITK version to 0.7.0.dev54

This update to SimpleITK includes the following:
 Fix for mantis 3157
 Improved compilation time with parallelism
 Improved VS9 compiler check
 Windows numpy size conversions fix

Additional tweaks to external file include:
 Adding cmake flag to remove git hash for version.
 Adding cmake variables for git tag and url. Consistent with ITKv4 external
project description.
 Remove extra CMake module include
 Remove obsolete comment regarding unsupported shared library build. See r22133 [1]

[1] http://viewvc.slicer.org/viewvc.cgi/Slicer4?view=revision&revision=22133

From: Bradley Lowekamp <blowekamp@mail.nih.gov>

git-svn-id: http://svn.slicer.org/Slicer4/trunk@22165 3bd1e089-480b-0410-8dfb-8563597acbee