This change is part of a sequence of changes to allow the TriBITS system to be
used as a meta-build system where Trilinos will be treated as nothing more
than another repository of packages along with any other repository of
packages.  To do this, we can't distringuish between "package" and "extra
packages".  They are all just "packages".  Same goes for TPLs.

In discussing this in great detail with Chris Baker, we also decided that it
makes sense to put PacakgesList.cmake and TPLsList.cmake right in the top
level directrory to make them more prominent.  As part of a similar argument,
I have also moved the copyright file into the main directory and the
Version.cmake file.  These changes also make this consistent with the general
idea of a Repostory (see README.META_PROJECTS).