Allow use of system MPI.

The pre-existing cmake script magic for falling through
to calling FindPackage(MPI) to get the system MPI works fine,
as long as we use the name MPI instead of OPENMPI, which
is just the variant of MPI we happen to build.

NOTE: You must set CDAT_BUILD_ESMF_COMM accordingly as we have
no introspection that will detect the particulat flavor you have.
add regression test image for mac dashboards

Need a second image for mac because vistrails won't produce the exact
same sized image as on linux for some reason.
Mac bug in cairo makes this image wrong but necessary - in interactive
use the actual image looks right.
Merge remote-tracking branch 'devel/add_mac_regression_test'

* devel/add_mac_regression_test:
  add regression test image for mac dashboards
Set INCLUDE_PYTHONHOME_PATHS to OFF for UV-CDAT ParaView build
Got UV-CDAT to start saying UV-CDAT instead of Python under Mac
Do not download source at the root level

It confused the make target
Updated location of pixman download source location
Merge remote-tracking branch 'devel/uvcdat_but_112_update_paraview_external'

* devel/uvcdat_but_112_update_paraview_external:
  Set INCLUDE_PYTHONHOME_PATHS to OFF for UV-CDAT ParaView build
  add regression test image for mac dashboards
Merge remote-tracking branch 'devel/uvcdat_fix_source_locations'

* devel/uvcdat_fix_source_locations:
  Updated location of pixman download source location
  Do not download source at the root level
Merge remote-tracking branch 'devel/MacName'

* devel/MacName:
  Got UV-CDAT to start saying UV-CDAT instead of Python under Mac
Merge remote-tracking branch 'remotes/devel/allow_system_mpi'

* remotes/devel/allow_system_mpi:
  Allow use of system MPI.
meryem use http protocol
Merge remote-tracking branch 'devel/meryem_use_http' into devel-master

* devel/meryem_use_http:
  meryem use http protocol
Fixing typo that causes extra downloads for dashboards.

There are sample files which get downloaded when building
UV-CDAT but these aren't needed by the dashboard builds but
due to a typo they are being downloaded anyways. Fixing it to
get rid of this wasteful download.
Merge remote-tracking branch 'devel/129_fix_cmake_typos' into devel-master

Conflicts:
	CMake/dashboard/meryem.cmake
Merge remote-tracking branch 'devel/meryem_use_http'
First step in enabling UV-CDAT testing data.

For now we just enable getting the testing data and
make the location of it a CMake variable. For ParaView,
I'm setting the value as well to be used there.
Merge remote-tracking branch 'devel/130_download_test_files' into devel-master
Renabling downloading sample data for dashboards and guarding tests.

It looks like 3 tests require the sample data to be available. So
I reenabled downloading the sample data for the dashboards. I also
guarded the tests to make sure that the sample data is downloaded
before enabling the tests.
Merge remote-tracking branch 'devel/129_fix_cmake_typos' into devel-master

Conflicts:
	CMake/dashboard/meryem.cmake