MLDS-170 Change access pattern -- db first, then look to remote.  Allows us to run of local "ADMIN" users during transition.
- Extract PostRequestBuilder
- Better check for no-user-found from remote web auth
MLDS-170 Map permissions from remote system
Map remote conditions to Spring Security exception types
Unit tests
Javadoc and cleanup
MLDS-170 Sniff error message for error codes, and show different errors during login