Merge pull request #48 from mlippert/widget-refactor

restore changes lost by merge
First pass selectgroup tests

many still fail - event handling is different than radio button
includes selectGroup
SelectOneQuestion work

* eventManager is required
* added submitButton member
* added event id for submit requested
* added handlers for choice selection and submit button being pressed
* draw has a preliminary implementation

now the Button widget needs work to support the requirements of the SelectOneQuestion