Upgrade to 2.4.0 version of GWT and GWT Maven plugin.
Upgrade to 2.4.0 version of GWT and GWT Maven plugin.

The latter now includes my -XdisableRunAsync patch, so we no longer need my
patched version of the 2.3.0 GWT Maven plugin.

threerings/playn,threerings/playn,ruslansennov/playn,ruslansennov/playn,threerings/playn,threerings/playn,ruslansennov/playn