Simple sanitization of cli commands. Fixes: #97
POST to /vac_register now lets us set the vac register URL
Also include lightweight git tags when generating the version string.
added a local backend for the tests

The tests currently fail in netword-restricted build environments, it is
solved by starting a local backend for each test suites.

The backend is built on top of python's BaseHTTPServer, which is already
present at build time. It simply answers empty HTTP responses (204) to
any GET, HEAD or POST requests.

Conflicts:
	tests/badvarnishd.sh
	tests/util.sh
Merge pull request #101 from Dridi/offline_test_suite

Add a local backend for the tests
Make tests slightly more freebsd friendly.