FindPythonModules: use a function

Prevent unnecessary scope pollution.

Change-Id: If268d5fcbcf4edd7b5dcac62fa567ca4cf634082
FindPythonModules: search if not found

It might have been installed to satisfy the module requirement since the
first check.

Change-Id: I1775c3d060cbf75bec383309fd026a4cf7b348a3
vtkmpi4py: empty out Py_{UN,}BLOCK_THREADS

Cython will put _save in a WITH_THREAD block, so it isn't available
without threads. Just having empty code works just as well.

Change-Id: Ia5c63824916a5f14b1d0cf6833e12ed40bf4f71b
Check if the selection array exists before dereferencing it.

Change-Id: I63a6952a0d4493d57096d6b544f03ed9a6f0b107
Fix vtkAbstractPolygonalHandleRepresentation3D visibility

When the default position of the camera is not looking at 0,0,0 (default
handle position) the handle representation was never displayed.
Its bounds were culled by the renderer which prevented the handle actor
from being rendered which prevented the representation from calling
BuildRepresentation() which prevented the actor to have its correct
position set.

Change-Id: I36bffca7fef86c1493ff6869522fb89824390d06
Merge topic 'fix-vtkabstractpolygonalhandlerepresentation3d' into master

f8fe12a6 Fix vtkAbstractPolygonalHandleRepresentation3D visibility
Merge topic 'control-points-selection' into master

81a76c77 Check if the selection array exists before dereferencing it.
Merge topic 'support-future-use-of-crossbar-io' into pv-master

12f6589c Properly override ApplicationSession c-tor, supports Crossbar.io.
Merge remote-tracking branch 'pvvtk/pv-master' into HEAD

* pvvtk/pv-master:

Change-Id: I9aab8d3babb04ae43215561456eb396dc6a0f325
vtkPStreamTracer: remove unused function

Change-Id: I9e911bdad3ce80f6a1803634b78e31d4ceefb485
Merge topic 'fix-mpi4py-without-threads' into master

0714be97 vtkmpi4py: empty out Py_{UN,}BLOCK_THREADS
Merge topic 'dashboard-warnings-20140828' into master

359f53b7 vtkPStreamTracer: remove unused function
Merge topic 'python-find-module' into master

9b2bba13 FindPythonModules: search if not found
a2f0bf4d FindPythonModules: use a function