Cleared just a small portion of the great clouds of crack smoke and made

the timers not invalidate _every fucking tick_, even if they're not even
showing!!!


git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@3569 542714f4-19e9-0310-aa3c-eee0fc999fb1

src/java/com/threerings/media/HourglassView.java

@@ -81,7 +81,7 @@ public class HourglassView extends TimerView
         super.tick(tickStamp);
 
         // check if the sand should be updated
-        if (tickStamp > _sandStamp) {
+        if (_enabled && _running && tickStamp > _sandStamp) {
 
             // update the sand frame
             setSandTrickleY();

src/java/com/threerings/media/TimerView.java

@@ -315,6 +315,10 @@ public class TimerView
     // documentation inherited
     public void tick (long now)
     {
+        if (!_enabled) {
+            return;
+        }
+
         // Initialize the starting time if necessary
         if (_start == Long.MIN_VALUE) {
             _start = now - Math.round(_duration * _complete);