Hsp processor

Hsp preprocessor for Karma that makes it easy to run tests written as *.hsp files. The preprocessor is trivial and normally should be published as a separate npm module, but this would require that a compiler is available as a separate module. Checking-it in in this repo for now.

This PR depends on #28
Also #29 needs to be fixed before as there are currently some tests failing on FFox (a browser used on Travis).