Make simpler argument parser to work with more than one kernel per program.
2013-11-06  Antonio Gomes  <a1.gomes@sisa.samsung.com>

        Make WebCLKernel to have its own copy of the
        program source, in order to avoid accessing a
        possible program dangling pointer.

        Reviewed by NOBODY (OOPS!).

        Related to issue #335 (WebCLKernel might hold a dangling
        backpoint to WebCLKernel), but just a work around.

        Fixes a crash in the translated (opencl->webcl) smallpt demo.

        * Modules/webcl/WebCLKernel.cpp:
        (WebCore::WebCLKernel::WebCLKernel):
        (WebCore::WebCLKernel::getInfo):
        (WebCore::WebCLKernel::ArgumentList::ensureArgumentData):
        * Modules/webcl/WebCLKernel.h: