alpha/beta/rc/milestone releases are now valid versions!

src/com/dmdirc/updater/Version.java

         if (version.matches("^[0-9]+$")) {
             this.intVersion = Integer.parseInt(version);
             this.strVersion = null;
-        } else if (version.matches("^[0-9]+(\\.[0-9]+)*(\\-[0-9]+\\-g[a-z0-9]{7})?$")) {
+        } else if (version.matches("^[0-9]+(\\.[0-9]+)*((a|b|rc|m)[0-9]+)*(\\-[0-9]+\\-g[a-z0-9]{7})?$")) {
             this.intVersion = Integer.MIN_VALUE;
             this.strVersion = version;
         } else {