Merge pull request #2687 from ngokevin/unsub

unsub devs from comm when they're removed as collab (bug 1087276)
fix review history typo from debugging
Set stage/prod FxA URLs
Merge pull request #2688 from mstriemer/fxa-config

Set stage/prod FxA URLs
add new comm constants for version notes and public rev comment (bug 1090615)
make developer version note rather than rev comment (bug 1090615)