Update README.md

Adding trello board to readme
Adding some javadoc and other comments.  Code cleanup
Merge branch 'master' of http://github.com/CruGlobal/conf-registration-api
It was determined that the reason Chrome was having issues with reporting error messages was that any exception
(NPE for example) was allowed to fall all the way out of the endpoint method.  Simply catching any such exception
and wrapping it in a Resteasy ServerErrorException and throwing that will ensure that the proper headers are set
and the correct status code gets back to the client.
 - Custom error classes were removed
 - Custom `UnauthorizedException` was removed.  Resteasy has its own
 - All errors (non 2xx) responses are now reported by throwing the appropriate exception
  - the exceptions to the above are 502 bad gateway and 41? gone which have no defined exception
forgot to remove this class in previous commit
Merge pull request #82 from CruGlobal/undo-error-handling

Undo error handling fixes put in last week and replace with correct handling
Refactoring registration and conference processes to inject necessary services, and cut down on unneccessary injections in resource endpoints.
Add a null safe version of getCompleted() to the RegistrationEntity, and use this check in `RegistrationUpdateProcess` for readability
Removing this line b/c @hlbraddock brings up a good point that other conferences that don't accept online CC payments may still want to take advantage of early registration discounts
Merge branch 'master' into add-registration-total

Conflicts:
	src/main/java/org/cru/crs/api/ConferenceResource.java
	src/main/java/org/cru/crs/api/RegistrationResource.java