Enabled quiet Doxygen compilation.

doc/Doxyfile.in

@@ -557,7 +557,7 @@ LAYOUT_FILE            =
 # The QUIET tag can be used to turn on/off the messages that are generated
 # by doxygen. Possible values are YES and NO. If left blank NO is used.
 
-QUIET                  = NO
+QUIET                  = YES
 
 # The WARNINGS tag can be used to turn on/off the warning messages that are
 # generated by doxygen. Possible values are YES and NO. If left blank