Bug Fix/Feature: Make the spam of radar on open/close and login optional

Adds RadarAlertFlood and RadarAlertFloodLeaving
RadarAlertFloodLeaving requires RadarAlertFlood
Radar uses new announcements for these events.
These settings are off by default,
Find them in your local debug settings!

indra/newview/app_settings/settings.xml

@@ -7790,6 +7790,28 @@ This should be as low as possible, but too low may break functionality</string>
       <key>Value</key>
       <integer>1</integer>
     </map>
+    <key>RadarAlertFlood</key>
+    <map>
+      <key>Comment</key>
+      <string>Show the flood of people arriving and (if RadarAlertFloodLeaving) leaving when you login and when you open/close the Radar with RadarKeepOpen off.</string>
+      <key>Persist</key>
+      <integer>1</integer>
+      <key>Type</key>
+      <string>Boolean</string>
+      <key>Value</key>
+      <integer>0</integer>
+    </map>
+    <key>RadarAlertFloodLeaving</key>
+    <map>
+      <key>Comment</key>
+      <string>When activated along with RadarAlertFlood shows the flood of people leaving when you close the Radar with RadarKeepOpen off.</string>
+      <key>Persist</key>
+      <integer>1</integer>
+      <key>Type</key>
+      <string>Boolean</string>
+      <key>Value</key>
+      <integer>0</integer>
+    </map>
     <key>RadarAlertShowDist</key>
     <map>
       <key>Comment</key>