Add a .gitignore file

A .gitignore file will help to keep the repository cleaner and will
hopefully make it slightly easier to use.  This has been configured
only to ignore the temporary files created by gedit (*~).
Remove temporary files

The temporary files which are created by gedit were stored in the
repository which made it cluttered and hard to use.  These have all
been removed and should now be caught by the .gitignore file.
Remove robot_setup_tf

This package is lifted straight from a ros tutorial and does not relate
to enterprise at all.  This package has been removed in favor of
creating a separate package for enterprise's tf tree.
Remove rosserial

This directory was placed in the repository after installing rosserial
from source.  The directory is itself a repository and so will not be
displayed on github and should also not be included in the repository.