Update form elements with new BS 3 equivalents

Global replace of form elements removed or renamed in Bootstrap 3:

* .form-search replaced with .form-inline
* Change .control-group to .form-group
* Replace .radio.inline and .checkbox.inline with -inline
* Update .btn to .btn.btn-default where used as submit button

This is not a complete migration of the forms; the other form
changes required by BS 3 (adding column widths to controls,
wrapping checkboxes and radio buttons in an extra div) need
to be done on a form-by-form basis.