Create authentication "vault" for monitors and reactions

[madflojo]

One commonly annoying thing is having to add API keys, Username/Passwords, SSH Keys and what not to each monitor/reaction manually. It would be best to create a "key vault" that allows users to put in those details once and use a select box for each monitor/reaction.

At some point it would be worthwhile to introduce multiuser accounts and I see the key vault being an admin function. This would let basic users setup monitors without knowing any sensitive details about the target system.