Starting the refactor - s/value/label when creating a form row.

Thsi approach is better. There is an initial presentation stage of
creating a row - name, label, html attributes etc - then the stage where
the value and options are assigned. While it is an extra call to set the
value, this is normally covered by handle() or setValues() anyway.
Updating Form and un-breaking FormTest.
Fixing FormRowTextAreaTest.
Fixing FormRowTextTest.
Fixing FormRowSelectTest.
Fixing FormRowPasswordTest.
Fixing FormRowHiddenTest.
Fixing FormRowCheckboxTest.
FormRow - putting submit value logic in input().

This allows for complete removal of the child __construct
function. Fixing FormRowSubmitTest.