Update/Refresh apps-custom.js

Can the ucamprojectlight/static/javascripts/apps-custom.js file be updated with the master one at https://github.com/cambridgeuniversity/Project-Light/blob/master/javascripts/custom.js

The current one here does not properly support ProjectLight drop-down menus.

I can't see any version information in the file, so I can't say how out of date the file is.