2014-04-09  Antonio Gomes  <a1.gomes@sisa.samsung.com>

        implement nullable for WebCLContext::createCommandQueue and WebCLProgram::build
        Issue #511

        Reviewed by TrustMe.

        C++ side of this change should be in place already
        (exercised when parameter are omitted).

        * Modules/webcl/WebCLContext.idl:
        * Modules/webcl/WebCLProgram.idl: