Remove standard TriBITS includes (PHI Kanban #2719)

This results in less cluttered CMakeLists.txt files and speeds up the
configure a little.
Convert over to use TRIBITS_PACKAGE_DEFINE_DEPENDENCIES() (PHI Kanban #3570)

Using the function TRIBITS_PACKAGE_DEFINE_DEPENDENCIES() makes the
Dependencies.cmake file more compact but no less safe.  It also makes it easy
to find documenation.
Setting precon to None and simplify PL logic (PHI Kanban #3570)

This sets the preconditioner to None explicitly.

This causes the test that was throwing due to a bad cast (trying to create a
preconditioner with Ifpack) to returning all NaNs.  This is not consistent
with the other test returning NaNs.
Use TEST_COMPARE_FLOATING_ARRAYS() instead of raw loop

This provides better error messages and cuts down on the amount of unit test
output.
Merge pull request #23 from bartlettroscoe/more_dtk_fixes_20141217

More dtk fixes 20141217