Options to configure MySQL for SSL and glance, keystone and nova clients.

The mysql module supports SSL but it wasn't accessible since the
arguments to configure it were unused. Add options to pass in the
CA, cert and private key paths to enable SSL in MySQL.

The second part of the patch reconfigures the connection line in the
glance, keystone and nova clients to use SSL by adding the ssl_ca
option.

Change-Id: I1f748fd7cfac110fc3170b235175623abfc9317b
Fixes: bug #1214606