(SERVER-30) Master SSL fail-fast

This commit adds fail-fast behavior to the master which requires that
the master's private key, certificate, and local CA certificate copy all
exist.
(SERVER-30) Relax required files for CA fail-fast

This commit changes the CA initialization fail-fast behavior to no
longer require the CA public key. Directories are also no longer
required, but will be created automatically if they don't already exist.
Merge pull request #214 from nwolfe/svr30-master-ssl-fail-fast

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