Fixes lastChange part of issue #22,
testRunner can now generate an HTML page during a test run,
using Chrome extension captureScreenshot().
The setup is funky:
open http://localhost:9696/atopwi/atopwi.html?ws=localhost:9222/devtools/page/4
with the correct page number read off the atopwi page,
then open devtools with testRunner and run the tests in DocGen/.
Out written back to the local server