Support binary-only distribution and use of plugins

A developer working on a Grails application currently requires access to ALL application source code in order to run the application. This is problematic for large, proprietary projects that need to protect source code. Hiring a new or remote contractor for even simple HTML work requires that the contractor be given access to the entire source code repository, posing a significant risk of unauthorized use of code that may have taken years of effort to develop. The support of binary-only plugins would provide a mechanism for key aspects of an application to accessible without risking unauthorized modification and use.