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 Sep 10 21:26:48 2014
    Checking network connection... OK
    Checking phonetisaurus dictionary file... OK
    Checking phonetisaurus program... OK
    git revision: 7bce3aae973fee1832f9d2bee52027835ae9ff66
    All checks passed