Move some code from Branches/OpenCL to trunk, related to threading and OpenCL:

Added Demos/ThreadingDemo showing how to use the cross-platform btThreadSupportInterface under Windows.
Added Demos/ParticlesOpenCL showing how to run the NVidia particle demo under OpenCL implementations by AMD, NVidia and MiniCL (CPU)

Demos/SharedOpenCL/btOclCommon.h

@@ -0,0 +1,42 @@
+/*
+Bullet Continuous Collision Detection and Physics Library, http://bulletphysics.org
+Copyright (C) 2006 - 2010 Sony Computer Entertainment Inc. 
+
+This software is provided 'as-is', without any express or implied warranty.
+In no event will the authors be held liable for any damages arising from the use of this software.
+Permission is granted to anyone to use this software for any purpose, 
+including commercial applications, and to alter it and redistribute it freely, 
+subject to the following restrictions:
+
+1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required.
+2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
+3. This notice may not be removed or altered from any source distribution.
+*/
+
+#ifndef BTOCLCOMMON_H
+#define BTOCLCOMMON_H
+
+#ifdef __APPLE__
+#ifdef USE_MINICL
+	#include <MiniCL/cl.h>
+#else
+	#include <MiniCL/cl.h>
+#endif
+#else
+	#ifdef USE_MINICL
+		#include <MiniCL/cl.h>
+	#else
+		#include <CL/cl.h>
+	#endif
+#endif //__APPLE__
+
+
+class btOclCommon
+{
+public:
+	static cl_context createContextFromType(cl_device_type deviceType, cl_int* pErrNum);
+};
+
+
+
+#endif // BTOCLCOMMON_H