(SERVER-30) Improve SSL fail-fast for master & CA

The first change in here adds fail-fast behavior to the master service so that it will fail to start if it finds it doesn't have its private key, certificate, and local CA certificate.  If all three of those files are missing, the entire set of SSL files will be generated.

The second change in here loosens the conditions for CA fail-fast so it no longer requires the CA public key, and it will automatically create the signed/ and requests/ directories if they don't exist.
The file tomfoolery here is a bit undesirable.  At least, the last `copy` should be inside a `finally`, so that if the test fails, it won't have deleted the test file.  However, it'd be better if this test was just completely sandboxed and didn't require temporarily deleting test files.