RESTEASY-802: Renamed GetRestful.getSubResourceClass() to
getSubResourceClasses() and restored original getSubResourceClass().
Merge branch 'Branch_2_3' of https://github.com/resteasy/Resteasy into Branch_2_3
Merge pull request #261 from ronsigal/Branch_2_3

Branch 2 3: RESTEASY-802