it's query string "title=" arg or from the actual contained title.
* Made use of this new function in various places where title-grabbing was being done manually.
* Made Editor.mouse_clicked() highlight and bail if there's already an open editor with a matching
title. (Previously, it only did this matching by id.)
* Wiki.load_editor() now looks to an open Link_pulldown's title field for the note's title, if
available.
* Link_pulldown formats "title=" query string args with MochiKit's queryString() to escape spaces
and such.
* Updated NOTE_LINK_PATTERN in wiki download view (untested currently).
* Refactored some of validator decorator to use clearer variable names internally.
* Validator decorator now supports treating arguments with default values as optional.
* controller.Notebooks.default() takes an optional note_id argument.
* controller.Notebooks.contents() takes an optional note_id argument.
* Wiki.js now makes use of these new controller APIs.
* Editor.js now takes a notebook_id argument to its constructor so it can properly make links.
