Switch to GWT 2.5.1 and GWTP 1.0-RC-2

Disabled `fragmentCount` setting (`gwt-maven-plugin` in `org.jboss.as:jboss-as-console-build`). When activated GWT compiler fails with 

    [ERROR] error optimizing:JSC_VIOLATED_MODULE_DEPENDENCY. module module52 cannot reference kvb, defined in module module27, since module27 loads after module52 at module52 line 23 : 0

Without `fragmentCount` the actual fragements size is 40 (which seems to be the same as before).