Story format header fixes

* Hopefully restored OS X's external story format path.
* The "ENGINE", "SUGARCANE" and "JONAH" story format template keywords
are now available to story format headers even without a header class,
for backwards-compatibility with prior custom formats, and to allow
custom story formats (which could be in the aforementioned OS X external
story format path) to access them in the internal story format path.
* Added 'nobr' to the default list of nested macros.
* Altered StoryInit's default text
* Updated the app version to 1.4.2.
* Updated jQuery.