DRTVWR-476: Defer #include "lleventtimer.h" until lleventfilter.cpp.

indra/llcommon/lleventfilter.cpp

@@ -38,6 +38,7 @@
 #include "llerror.h"                // LL_ERRS
 #include "llsdutil.h"               // llsd_matches()
 #include "stringize.h"
+#include "lleventtimer.h"
 #include "lldate.h"
 
 /*****************************************************************************

indra/llcommon/lleventfilter.h

@@ -33,9 +33,9 @@
 #include "stdtypes.h"
 #include "lltimer.h"
 #include "llsdutil.h"
-#include "lleventtimer.h"
 #include <boost/function.hpp>
 
+class LLEventTimer;
 class LLDate;
 
 /**