TrustEngine refactoring

[Brent Putman]

On 8/15/14 8:32 PM, Brent Putman wrote:
> I'll just go ahead and check it in. The existing wiring at least
> should be easy to fix.

I *think* I got the wiring for the signature stuff fixed up.

I haven't touched anything for the client TLS yet, so if there are tests
that actually exercise that stuff, we'll probably see the
SAMLMDClientCertAuthSecurityHandler action throw a
MessageHandlerException about being unable to resolve the trust engine
or the certificate name options.

I'll let Jenkins run the tests at this point and see what happens....