Look mum, no globals! Implement a RequestContext for HTMLForm, passed in the constru...

Look mum, no globals!  Implement a RequestContext for HTMLForm, passed in the constructor.  Currently this is optional with B/C; at a later date it should be made compulsory.  Doing this removes the need to call $form->setTitle() on every single use; only when you want to set the title to something other than the page context title.  Implemented the new syntax in a sample of forms.  Also fix a few minor errors in HTMLForm.php that my IDE complained about.