Implement FindThirdPartyOpenGL with the cmake official module.

This fixes issue #62 (only tested on fedora but I'm confident as it mostly uses the cmake module to find OpenGL).

cmake-modules/FindThirdPartyOpenGL.cmake

 # ---------------------------------
 # Finds OpenGL toolkit
 #
-# Sets OpenGL_FOUND
-# Sets OpenGL_LIBRARIES
-# Sets OpenGL_LIBRARY_DIRS
-# Sets OpenGL_LDFLAGS
-# Sets OpenGL_LDFLAGS_OTHERS
-# Sets OpenGL_INCLUDE_DIRS
-# Sets OpenGL_CFLAGS
-# Sets OpenGL_CFLAGS_OTHERS
+# Sets OPENGL_FOUND
+# Sets OPENGL_INCLUDE_DIR
 # ---------------------------------
 
-IF(WIN32)
-	FIND_LIBRARY(LIB_STANDARD_MODULE_GL opengl32)
-	FIND_LIBRARY(LIB_STANDARD_MODULE_GLU glu32)
-	IF(LIB_STANDARD_MODULE_GL AND LIB_STANDARD_MODULE_GLU)
-		debug_message( "  Found gl...")
-		TARGET_LINK_LIBRARIES(${PROJECT_NAME} ${LIB_STANDARD_MODULE_GL})
-		TARGET_LINK_LIBRARIES(${PROJECT_NAME} ${LIB_STANDARD_MODULE_GLU})
-		ADD_DEFINITIONS(-DTARGET_HAS_ThirdPartyOpenGL)
-	ELSE(LIB_STANDARD_MODULE_GL AND LIB_STANDARD_MODULE_GLU)
-		MESSAGE(WARNING "  FAILED to find gl...")
-	ENDIF(LIB_STANDARD_MODULE_GL AND LIB_STANDARD_MODULE_GLU)
-ELSE(WIN32)
-	INCLUDE("FindPkgConfig")
-	pkg_check_modules(OpenGL glu)
-
-	IF(OpenGL_FOUND)
-		debug_message( "  Found OpenGL...")
-		INCLUDE_DIRECTORIES(${OpenGL_INCLUDE_DIRS})
-		ADD_DEFINITIONS(${OpenGL_CFLAGS})
-		ADD_DEFINITIONS(${OpenGL_CFLAGS_OTHERS})
-		LINK_DIRECTORIES(${OpenGL_LIBRARY_DIRS})
-		IF(NOT(APPLE))
-			LINK_DIRECTORIES(${OpenGL_LIBRARY_DIRS}/mesa)
-		ENDIF()
-		FOREACH(OpenGL_LIB ${OpenGL_LIBRARIES} z)
-			SET(OpenGL_LIB1 "OpenGL_LIB1-NOTFOUND")
-			FIND_LIBRARY(OpenGL_LIB1 NAMES ${OpenGL_LIB} PATHS ${OpenGL_LIBRARY_DIRS} ${OpenGL_LIBDIR} NO_DEFAULT_PATH)
-			FIND_LIBRARY(OpenGL_LIB1 NAMES ${OpenGL_LIB} PATHS ${OpenGL_LIBRARY_DIRS}/mesa ${OpenGL_LIBDIR}/mesa NO_DEFAULT_PATH)
-			FIND_LIBRARY(OpenGL_LIB1 NAMES ${OpenGL_LIB})
-			IF(OpenGL_LIB1)
-				debug_message( "    [  OK  ] Third party lib ${OpenGL_LIB1}")
-				TARGET_LINK_LIBRARIES(${PROJECT_NAME} ${OpenGL_LIB1})
-			ELSE(OpenGL_LIB1)
-				MESSAGE(WARNING "    [FAILED] Third party lib ${OpenGL_LIB}")
-			ENDIF(OpenGL_LIB1)
-		ENDFOREACH(OpenGL_LIB)
-		ADD_DEFINITIONS(-DTARGET_HAS_ThirdPartyOpenGL)
-	ELSE(OpenGL_FOUND)
-		MESSAGE(WARNING "  FAILED to find OpenGL...")
-	ENDIF(OpenGL_FOUND)
-ENDIF(WIN32)
+find_package(OpenGL REQUIRED)
+if (OPENGL_FOUND AND OPENGL_GLU_FOUND)
+    target_link_libraries(${PROJECT_NAME} OpenGL::GL OpenGL::GLU)
+    include_directories(${OPENGL_INCLUDE_DIR})
+    add_definitions(-DTARGET_HAS_ThirdPartyOpenGL)
+else()
+    message(WARNING "  FAILED to find OpenGL...")
+endif()