1. Squawking partially completed

2. Added workspace to pipeline to track squawk challenges

3. Reviews XOR tests from last night and found many errors.  Spent too much
time finding the problem which turns out to be a limitation of PHP in working
with large numbers.  I wrote my own XORing function and all it well now.

4. In addition to the XOR function (sgXor) I implemented the rest of the
functionality needed for the SansGrid authentication.  I should spend a little
more time testing it.

5. Updated stub generator to generate all possible sensor-side squawks.
Merge branch 'master' of github.com:squidpie/sansgrid