tearDown does screenshot if it detects a failure. --ch19l006--
helpers to take screenshot and dump html in base.py. --ch19l007--
get filename for screenshots and dumps. --ch19l008--
add a deliberate test failure to check screenshotting. --ch19l009--
Revert deliberate test failure. --ch19l010--

This reverts commit 2624732383b4351c4bb31625ec1f739b27e6412a.
use wait_for in my lists test around url check. --ch19l012--
wait_for defined in base.py. --ch19l013--
define DEFAULT_WAIT in base. --ch19l014--
deliberately break url check in wait. --ch19l015--
Revert deliberately breaking url check. --ch19l016--

This reverts commit b0446526dcf71b43df192f9d5d89ea2f950b032e.
gitignore screendumps.
add phantom runner.js. --ch19l017--
temporarily break js test. --ch19l019--
Revert temporarily break js test. --ch19l020--

This reverts commit 7eb6cee8529de10af282072a6ae33bc933446440.