pygsm_demo can't find pygsm if run from git clone

[jwishnie]

If 'pygsm' is cloned out of git, but not installed with 'setup.py' the pygsm_demo script can't find the libraries.

[jwishnie]

These two patches fix by adding local 'lib' dir to syspath--this means pygsm_demo if run from a clone will always use the local copy of lib/pygsm (the one from the same repo)
http://github.com/jwishnie/pygsm/commit/069023083f0935c6b10a092de8285c30f797bac2
http://github.com/jwishnie/pygsm/commit/66c205570e7f04546adcb03b0640bb0afa0cd989