Comment 2 for bug 1928126

I've started a collab branch: collab/gmcharlt/remove-xul-client

The approach I have in mind thus far is:

- remove the ability to build the XUL client
- remove places in the legacy Dojo and AngularJS code that try to invoke XUL interfaces when running inside a XUL client. Once this is complete, there should be no remaining references to isXUL() and window.IAMBROWSER
- remove the XUL chrome (and deal with any remaining references to Open-ILS/xul/staff_client/chrome/content/util/date.js, which gets a (broken) symlink from /openils/var/web/opac/common/js.date.js) There is other JavaScript that copies from chrome to server during installation that may need to be tracked down as well.
- trim Open-ILS/xul/server of everything that isn't still in use (such as the user permissions editor. It might not be a bad idea to move those remaining bits elsewere (say, Open-ILS/web/xul) so that the final results drops Open-ILS/xul from the source tree entirely.