Force GWT compilation to use
Fixes build issues on Windows where the default charset isn't
<jvmarg value="-Xss2M"/> <!-- increase if you see a StackOverflowError -->
<jvmarg value="-Xmx1G"/>
<jvmarg line="${XstartOnFirstThread}"/>
+ <jvmarg value="-Dfile.encoding=UTF-8" />
<arg line="-war"/>
<arg value="${build.war.dir}"/>
<arg line="-logLevel INFO -style pretty"/>
