ENH: Simplify ImageToTubeRigidMetric.

Change-Id: I865b5cc8e0a4904905963de285af7b644f48d1bf
ENH: ImageToTubeRigidMetric: use CompensateSummation.

Improves robustness.

Change-Id: I7100e7328223d34cd4525e875ce6aeea2fb393a6
BUG: Create Python virtualenv at configure time. #95.

The virtualenv needs to available to install the tubetk packages for testing.
ENH: Add Notebook example for converting tubes to NumPy array.
Merge pull request #96 from thewtex/Virtualenv-at-configure

BUG: Create Python virtualenv at configure time. #95.
BUG: Explicit link against PYTHON_LIBRARIES for Mac.
Merge pull request #98 from thewtex/MacPythonModuleLibrary

BUG: Explicit link against PYTHON_LIBRARIES for Mac.
ENH: Factor out tube point weight calculation.

Change-Id: Ieea9acbd082daa5d1fd3c97a5b8593297ad43ed5
COMP: Check for svn executable when using superbuild
COMP: Use https instead of http for GitHub
STYLE: Minor CMake-related style fixes
ENH: Bump LIBSVM tag to match current HEAD
Merge pull request #100 from jamiesnape/CMakeSuperbuildFixes

COMP: Various minor superbuild-related fixes
FIX: Filename mismatch in TubeGraphToImage test.
Merge pull request #101 from rkwitt/Fix-Tests

FIX: Filename mismatch in TubeGraphToImage test.
BUG: Add pytables to the testing virtualenv. #103

Change-Id: I6b392fe62f45e2524bd91d901d46ad6ce523e0b0
ENH: TubeTK_USE_PYQTGRAPH OFF by default.

Larger dependencies.

Change-Id: If403c347613427ac578bf9692299eb5aae75a6ef
Merge pull request #99 from thewtex/ModelPointWeights

Model point weights
ADD: FindConsistentPython.cmake

     This adds FindConsistentPython.cmake to find Python libs and
     include directories consistent with the found interpreter.
     This has apparently been an issue for a long time and has
     been reported by many users.

     FindConsistentPython.cmake is an adaption from the Google
     code project:

     http://code.google.com/p/numexpr/

     where the authors have adjusted the original FindPythonLibs
     to accomplish the aforementioned task.
Merge pull request #97 from thewtex/TubeTKPython

ENH: Add Notebook example for converting tubes to NumPy array.