upslug2: Update to git repository

This has two improvements over the current version. An autotools fix and
application of the wrt350v2 patch.

Cleaned up Makefile as a result of makefiles being fixed.

Note that this package is not really used as it depends on orion, which is
classified as broken.

This is the last package that uses svn in the tree.

Signed-off-by: Rosen Penev <rosenp@gmail.com>