Don't show status message in 'FindGLM' if 'QUIET' option is set.

The 'QUIET' option of 'find_package' sets the 'GLM_FIND_QUIETLY' option.
This patch makes FindGLM suppress output when this is the case.

util/FindGLM.cmake

@@ -59,5 +59,7 @@ FIND_PACKAGE_HANDLE_STANDARD_ARGS(GLM DEFAULT_MSG
 IF(GLM_FOUND)
     SET(GLM_INCLUDE_DIRS "${GLM_INCLUDE_DIR}")
 
-    MESSAGE(STATUS "GLM_INCLUDE_DIR = ${GLM_INCLUDE_DIR}")
+    IF(NOT GLM_FIND_QUIETLY)
+        MESSAGE(STATUS "GLM_INCLUDE_DIR = ${GLM_INCLUDE_DIR}")
+    ENDIF(NOT GLM_FIND_QUIETLY)
 ENDIF(GLM_FOUND)