Add missing public/private function definition to Controller functions.
Add "action_" to *every* public Controller function (171 places).  This is probably too much, so we'll undo a few next.
Manually fix issues arising from adding "action_" to public Controller functions.
- remove "action_" from all get_siblings() and get_display_context() callbacks
- remove "action_" from Controller_ServerAdd::add() callback
- remove "action_" from Controller_Reauthenticate::valid_password() callback
- remove "action_" from Controller_L10nClient::l10_form() callback
- remove "action__" from Controller_ThemeOptions::validate_page_size() callback
- change $this->index to $this->action_index in Controller_Languages
- change $controller->add to $controller->action_add in unit test classes
- change $controller->update to $controller->action_update in unit test classes
Merge pull request #272 from shadlaws/controller_function_names

Controller function names