Fix Class.newInstance() deprecation warnings.

core/src/main/java/com/threerings/crowd/data/PlaceConfig.java

@@ -56,7 +56,7 @@ public abstract class PlaceConfig extends SimpleStreamableObject
         log.warning("Providing backwards compatibility. PlaceConfig." +
                     "createController() should be overridden directly.");
         try {
-            return (PlaceController)cclass.newInstance();
+            return (PlaceController)cclass.getConstructor().newInstance();
         } catch (Exception e) {
             log.warning("Failed to instantiate controller class '" + cclass + "'.", e);
             return null;

core/src/main/java/com/threerings/crowd/server/PlaceManager.java

@@ -461,7 +461,7 @@ public class PlaceManager
     protected PlaceObject createPlaceObject ()
     {
         try {
-            return getPlaceObjectClass().newInstance();
+            return getPlaceObjectClass().getConstructor().newInstance();
         } catch (Exception e) {
             throw new RuntimeException(e);
         }

core/src/main/java/com/threerings/presents/server/InvocationManager.java

@@ -155,13 +155,12 @@ public class InvocationManager
         // create a marshaller instance and initialize it
         T marsh;
         try {
-            marsh = mclass.newInstance();
+            marsh = mclass.getConstructor().newInstance();
             marsh.init(_invoid, invCode, _standaloneClient == null ?
                 null : _standaloneClient.getInvocationDirector());
-        } catch (IllegalAccessException ie) {
-            throw new RuntimeException(ie);
-        } catch (InstantiationException ie) {
-            throw new RuntimeException(ie);
+        } catch (NoSuchMethodException | InvocationTargetException | IllegalAccessException |
+                 InstantiationException ee) {
+            throw new RuntimeException(ee);
         }
 
         // register the dispatcher

core/src/main/java/com/threerings/presents/server/PresentsServer.java

@@ -113,7 +113,7 @@ public class PresentsServer
                 try {
                     log.info("Invoking test module", "mod", testmod);
                     Class<?> tmclass = Class.forName(testmod);
-                    Runnable trun = (Runnable)tmclass.newInstance();
+                    Runnable trun = (Runnable)tmclass.getConstructor().newInstance();
                     trun.run();
                 } catch (Exception e) {
                     log.warning("Unable to invoke test module '" + testmod + "'.", e);