Move the server add module files to their new homes (rename-only commit).

--HG--
rename : modules/server_add/controllers/admin_server_add.php => modules/server_add/classes/ServerAdd/Controller/Admin/ServerAdd.php
rename : modules/server_add/controllers/server_add.php => modules/server_add/classes/ServerAdd/Controller/ServerAdd.php
rename : modules/server_add/helpers/server_add_event.php => modules/server_add/classes/ServerAdd/Hook/ServerAddEvent.php
rename : modules/server_add/helpers/server_add_installer.php => modules/server_add/classes/ServerAdd/Hook/ServerAddInstaller.php
rename : modules/server_add/helpers/server_add_theme.php => modules/server_add/classes/ServerAdd/Hook/ServerAddTheme.php
rename : modules/server_add/models/server_add_entry.php => modules/server_add/classes/ServerAdd/Model/ServerAddEntry.php
rename : modules/server_add/helpers/server_add.php => modules/server_add/classes/ServerAdd/ServerAdd.php
rename : modules/server_add/css/server_add.css => modules/server_add/media/server_add.css
rename : modules/server_add/js/server_add.js => modules/server_add/media/server_add.js
rename : modules/server_add/views/admin_server_add.html.php => modules/server_add/views/admin/server_add.html.php
rename : modules/server_add/views/server_add_tree.html.php => modules/server_add/views/server_add/tree.html.php
rename : modules/server_add/views/server_add_tree_dialog.html.php => modules/server_add/views/server_add/tree_dialog.html.php
Fix the server add module class declarations.
Add the server add module transparent-extension-enabling files.
Search and replace in server add module (96 places).
Search and replace manually in server add and gallery modules (2 places in comments).
Merge pull request #245 from shadlaws/k3_server_add_module_translate

K3 server add module translation.