id is now optional for labelgroup widgets

if no id is supplied in the config, it will generate one.
Merge branch 'upstream/master'
Use a utility function to get the config id or auto generate one specific to the class

Done for LabelGroup, LineGraph, Carousel, Image and CaptionedImage. Still probably should be done for button, sketch, legend, barchart, slider...
a little formatting for the testing readme
adding tests, removing litekey from linegraph
Merge pull request #22 from mlippert/widget-refactor

config id is now optional for some widgets
Merge pull request #23 from jvish/review

Review
few more tests drawing graph in page. Before I go further we should discuss style and coverage.  Cleaned up id assignment in lineGraphTests (ok, Seann, you were right, it's a useful test.)
Merge branch 'upstream/master'