- Added a test in configure for the version of libPropList that is installed

on the system. Further compilation will be aborted if the version of
  libPropList that is found is older than expected. Hopefully this will make
  go away some annoying messages from people unable to read the release
  notes.
- Implemented periodic synchronization of user defaults in WINGs and
  notification when user defaults gets changed.
- Fixed the color panel to compile (someone in charge with it check if its
  ok, I only changed where the compiler complained, didn't go through the
  code).
- Misc fixes, related to latest changes in wrlib.

aclocal.m4

@@ -36,6 +36,39 @@ CPPFLAGS="$CPPFLAGS_old"
 ])
 
 
+dnl
+dnl WM_CHECK_PROPLIST_VERSION(MIN_VERSION, [ACTION-IF-FOUND [,ACTION-IF-NOT-FOUND]])
+dnl
+AC_DEFUN(WM_CHECK_PROPLIST_VERSION,
+[
+CPPFLAGS_old="$CPPFLAGS"
+CPPFLAGS="$CPPFLAGS $inc_search_path"
+lPL_major_version=`echo $1 | sed 's/\([[0-9]]*\).\([[0-9]]*\).\([[0-9]]*\)/\1/'`
+lPL_minor_version=`echo $1 | sed 's/\([[0-9]]*\).\([[0-9]]*\).\([[0-9]]*\)/\2/'`
+lPL_micro_version=`echo $1 | sed 's/\([[0-9]]*\).\([[0-9]]*\).\([[0-9]]*\)/\3/'`
+AC_MSG_CHECKING([whether libPropList is newer than $1])
+AC_CACHE_VAL(ac_cv_lib_proplist_version_ok,
+[AC_TRY_LINK(
+[/* Test version of libPropList we have */
+#include <proplist.h>
+
+#if !defined(PROPLIST_VERSION) || PROPLIST_VERSION < $lPL_major_version*10000 + $lPL_minor_version*100 + $lPL_micro_version
+#error libPropList on this system is too old. Consider upgrading to at least $1
+#endif
+], [], 
+eval "ac_cv_lib_proplist_version_ok=yes", 
+eval "ac_cv_lib_proplist_version_ok=no")])
+if eval "test \"`echo '$ac_cv_lib_proplist_version_ok'`\" = yes"; then
+  AC_MSG_RESULT(yes)
+  ifelse([$2], , :, [$2])
+else
+  AC_MSG_RESULT(no)
+ifelse([$3], , , [$3
+])dnl
+fi
+CPPFLAGS="$CPPFLAGS_old"
+])
+
 
 dnl
 dnl WM_CHECK_REDCRAP_BUGS(prefix,bindir,libdir)