ZP-680 Bump to version 2.3 to go into develop, fix z-push.org link.

Released under the Affero GNU General Public License (AGPL) version 3.

composer.json

 {
 	"name": "z-push/z-push",
 	"description": "Z-Push is an open-source application to synchronize ActiveSync compatible devices",
-	"version": "2.2.2",
-	"time": "2015-07-29",
-	"homepage": "http://zpush.org/",
+	"version": "2.3.0",
+	"time": "2015-09-02",
+	"homepage": "http://z-push.org/",
 	"license": "AGPL-3.0",
 	"require": {
 		"php": ">=5.2.0"