WebCL Conformance test suite update.

    Fixing issues mainly to take care of the review comments from reviewers.
    1. [Khronos Issue#21] getPlatforms in resources/cl_utils.js is misnamed.
    2. Adding test cases for API's releaseAll. [SRA Issue#249]
    3. createContext() does not reflect the Specification. [SRA Issue#246]
    4. [Khronos Issue#14] Move test cases for HTML elements to extension/WEBCL_html_image.
    5. [Khronos Issue#2]    Correct value used to create buffer, across files

Contributors :
 SRI-B : Shilpa Shri, Sharath Kamath.
 SRA : Antonio, Steven and Igor.

 Details on changes is available at master_r12132013 branch:
 https://github.com/SRA-SiliconValley/webkit-webcl-conformance.git.