weblogic-certificate plugin

Initial version of the weblogic-certificate plugin

Introduces 2 new Containers:
- CustomTrustKeyStore
- CustomIdentityKeyStore

and 2 Deployables
- TrustCertificateSpec
- IdentityCertificateSpec

and an SSL Channel restart contributor
Well, I was thinking "what if the user has reconfigured the deployment step"? Or what if they added a "update my CMDB" step at order 89, which should happen at the _end_ of the deployment?

I agree that, assuming that we stick with defaults, there should be no reason to change this. But since we give people the option to mess with defaults, hard-coded orders can be a source of problems.