Support max-listen-sockets parameter in zope.conf (for ZServer CONNECTION_LIMIT).

lib/python/Zope/Startup/handlers.py

@@ -101,6 +101,10 @@ def http_realm(value):
 def security_policy_implementation(value):
     value not in ('C', None) and _setenv('ZOPE_SECURITY_POLICY', value)
 
+def max_listen_sockets(value):
+    import ZServer
+    ZServer.CONNECTION_LIMIT = value
+
 # server handlers
 
 def root_handler(config):

lib/python/Zope/Startup/zopeschema.xml

@@ -557,4 +557,15 @@
 
   <section type="zoperunner" name="*" attribute="runner"/>
 
+  <!-- the below should go into the ZServer package, but I can't quite
+   figure out how to put it there -->
+
+  <key name="max-listen-sockets" datatype="integer"
+       handler="max_listen_sockets" default="1000">
+     <description>
+       The maximum number of sockets that ZServer will attempt to open
+       in order to service incoming connections.
+     </description>
+  </key>
+
 </schema>