Bug #3829: Including the headers that are required for context sharing
Bug #3829: Added methods for verifying is a device is share-capable and for enabling the shared CL-GL context. Changed how the preferred vendor is located.
Bug #3829: CL-GL context sharing can now be enabled through specifying the platform and device with a flag
Bug #3829: Added methods to check if a given extension is supported by a device or not
Bug #3829: Changed the implementation of SpecifyPlatform.... to allow the creation of the shared CL-GL context