JCLOUDS-602 - Add support for volumeType, iops and encrypted to EC2 volumes

Note - still missing adding these to the createVolume* methods, but
that's going to involve a non-trivial change to something like
CreateVolumeOptions.class rather than the current simple arguments.
For new classes, oh yeah, lots of wonderful new things without even going *that* far. =) But with existing classes, I tend to just work with what they got.