fix wiki.php createAction

[stephengaito]

• add missing use_pastebin in all uses of $this->_view('render' ... );

• add USE_PAGE_METADATA to create initial JSON (title) metadata in $content of createAction.

• fix use of APP_DIR in wiki.php createAction: the original $filepath did not use the APP_DIR trimmed $page value... it now does. (This would show up as a problem when the Wikitten wiki is used as a sub directory of a website).