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.
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'

* devel/129_fix_cmake_typos:
  Renabling downloading sample data for dashboards and guarding tests.
  Fixing typo that causes extra downloads for dashboards.

Conflicts:
	CMake/dashboard/meryem.cmake