ICE-9552 Changed bridge.js[ice.core] dependency to icepush.js[ice.push] from 'requires' to 'depends-on' so that only ordering is applied without forcing the load of ICEpush code when library is missing. Modified BridgeSetup to load icepush.js[ice.push] resource only when ICEpush library is present.

git-svn-id: http://anonsvn.icesoft.org/repo/icepush/trunk/icepush@37698 1de00972-ac04-4911-a46b-06793c8d78d9