added security services class, tests and required enums
Merge remote-tracking branch 'upstream/master'
added a class that maps from security services to cryptographic algorithms
Merge pull request #22 from jmaheswaran/master

Added SecurityServices, SecurityServicesTest classes, Algorithm and SecService enums
Merge pull request #21 from darylseah/master

Protobuf writing/reading support on KeyVersions.
Updating of protos.

- Switched to saner filenames (discovered java_outer_classname).
- Changed string type to enum Type.
- Extension numbers are now 10000 + <enum type number> (convention).
- Removed IV from AES proto.
- Add skeleton for Key proto.
Add KeyVersionInfo annotation.

- For annotating KeyVersions with (1) the proto type
  and (2) the compiled proto class.
- KeyVersion class now automagically sets the key version type
  when building the data proto and registers the required
  proto extensions when reading the data proto.
- Updated AES and HMAC key versions to use the annotation.

- (Also removed IV proto persistence from AESKeyVersion.)
Add @Documented to StoreDriverInfo annotation.

- Makes the annotation show up in the Javadoc of driver implementations.
- Same thing was added to KeyVersionInfo.