Custom output gamma, on behalf of Jacques; see issue #666

rtengine/rtengine.h

@@ -319,6 +319,8 @@ namespace rtengine {
 /** Returns the available working profile names
   * @return a vector of the available working profile names */
     std::vector<std::string> getWorkingProfiles ();
+/** return gamma	*/
+    std::vector<std::string> getGamma ();
 
     /** This class  holds all the necessary informations to accomplish the full processing of the image */
     class ProcessingJob {