Placeholder for specialized snapshot_tribits.py script (TriBITS #26)

For now this is just a symlink to python_utils/snapshot-dir.py.  Later, I will
specialize this script to allow for snapshotting only specific components and
files.
Fix make dashboard target (TriBITS #26)

Just needed to fix a single path.  There is no automated testing for the
'dashboard' target.  I need to figure out how to unit test as much of the
'dashboard' target as I can.
Moving out non-core functionality with calls (TriBITS #26)

The generation of XML dependnecy files is not core functionality so I moved it
out into a separate module and call it if the directory tribits/ci_support/
exists.

The 'dashbaord' build target is not core functionality so I moved it out into
a separate module and call it if the directory tribits/ctest_driver/ exists.

The goal is the shrink the size of "core" TriBITS as much as possible.