WebCL Conformance test suite update for review.

    Fixes the below issues ::

    Added functionality tests for enqueueWriteBufferRect
    Removed redundant file : bufferRectOperations.html.
    Refactor cl_webcl_waitForEvents.html to make it in par with spec
    Refactor WebCLKernel :: getWorkGroupInfo API test cases.
    Making enqueue{Read, Write} operations calls as unblocking, when waited on userevents.

    Contributors :
    SRI-B : Shilpa Shri, Sharath Kamath, Gajendra N.
    SRA : Antonio Gomes and Steven Eliuk.