merged ocl module from ocl branch (it's not quite usable yet; at least on Mac)

modules/ocl/doc/structures_and_functions.rst

@@ -0,0 +1,23 @@
+Data Structures and Functions
+=============================
+
+.. highlight:: cpp
+
+ocl::Info
+---------
+.. ocv:class:: ocl::Info
+
+this class should be maintained by the user and be passed to getDevice
+
+ocl::getDevice
+------------------
+Returns the list of devices
+
+.. ocv:function:: int ocl::getDevice(std::vector<Info>& oclinfo, int devicetype = CVCL_DEVICE_TYPE_GPU)
+
+    :param oclinfo: Output vector of ``ocl::Info`` structures
+    
+    :param devicetype: One of ``CVCL_DEVICE_TYPE_GPU``, ``CVCL_DEVICE_TYPE_CPU`` or ``CVCL_DEVICE_TYPE_DEFAULT``.
+    
+the function must be called before any other ``cv::ocl`` functions; it initializes ocl runtime.
+