Added load-path and asdf functions to module.lisp.
Deleted contrib folder
Added functions to initialize *load-path* from
stumpwm-contrib. *load-path* is now a list of pathnames where asdf
systems have been found.  In order to add a path to load-path the
function add-to-load-path checks if an asd file exists in the path, then
it checks if the path has been registered in asdf:*central-registry* and
in *load-path* it updates both accordingly.  If the path doesn't contain
an asd file, then it returns the old *load-path*.  The functions
find-module load-module and list-modules now operate across these paths
and list the stems of any asd files found in those paths.

To test this (assuming you've already setup and built stumpwm
with *contrib-dir* set to /path/to/stumpwm/contrib):
git pull
git checkout load-module
git clone git@github.com:stumpwm/stumpwm-contrib.git contrib
make

This branch breaks *contrib-dir* and (load "/path/to/contrib/blah.lisp")
calls in your .stumpwmrc!

In order to write you're own module:
(ql:quickload "quickproject")
(quickproject:make-project "/path/to/project" :depends '("stumpwm")
:license "GPLv3" :author "Anna Y. Mouse")
Then hackaway at project.lisp in project dir, probably need to add
:stumpwm to the package.lisp file.  When you're ready:
(add-to-load-path "/path/to/project")
(load-module "project")
Fixing load-path not being set properly bug
Merge branch 'load-module'