JBDS 7x Download Runtimes backwards compat patch

Nick has indicated we may be able to get a patch into 7.x if we move very fast. The question now becomes, what kind of patch do we want?

Here are the patch types I can make to attempt to ensure no breakage:

1) The "Hide-It" Patch - do NOT show a download-runtime object if requiresCredentials label is set to any value other than false.

2) The "No-Obvious-Change" patch - if requiresCredentials is set, pretend this downloadRuntime has no downloadUrl (so it continues to behave as it does today, showing a wizard page with a hyperlink to the project page for use by web browser)

3) The "I-Want-It-All" patch - see if git cherry-pick works and we can move the entire new functionality over without a breakage. (OH SO RISQUÉ)

These are our three choices. I vote for 1) or 2). I think 3) is very risky since we haven't even had time to fully test in master. We should avoid 3).