Simple diagnostic tool for Jasper

This tool should allow us to get a clear view of what's been configured on the clients Pi, and maybe give them some information about what to fix as well. Any other checks we should add, send me as comments to this PR and I'll upgrade the script.

This is the output in diagnostic.log:

    Starting jasper diagnostic
    Wed 10 Sep 2014 10:03:11 BST
    wget --quiet --spider http://google.com
    Checking internet connection...OK
    [ -e ../phonetisaurus/g014b2b.fst ]
    Checking phonetisaurus...OK