AngularJS defines custom HTML attributes (called "directives"). In order for
Komodo's codeintel to pick them up, an XML DTD catalog needs to be defined for
Angular. Angular does not provide one, so the seemingly easiest way to do this
was to piggy-back off of the HTML5 DTD and add Angular directives to that.

Those directives can be found here:

    https://docs.angularjs.org/api/ng/directive

All I've done is copied the html5 catalog's files, renamed "html5.dtd" to
"ng.dtd", modified "catalog.xml" appropriately, and added by hand each directive
to "ng.dtd". When I say "added by hand", I had to look up each directive, and
infer based on its documentation which HTML elements it could be added to.
Obviously you could just add all directives to the "coreattrs" HTML 5 entity and
call it a day. That is not "code intelligence" though.

Any subsequent updates to Angular will need to be reflected here and done so by
hand.
