Description of problem:
Buttons which add a new data input/output assignment is not localized.

See https://github.com/droolsjbpm/jbpm-designer/blob/6.0.x/jbpm-designer-client/src/main/resources/org/jbpm/designer/public/js/Plugins/propertywindow.js:
text: "[ New Data Input Assignment ]"
text: "[ New Data Output Assignment ]"
header: 'Assignment Type'

I think that there should be:
text: ORYX.I18N.PropertyWindow.addInputAssignment
text: ORYX.I18N.PropertyWindow.addOutputAssignment
header: ORYX.I18N.PropertyWindow.assignType

Please do not forget use default value and add this property to all supported localization files (en, ja, de, es, ru).

Version-Release number of selected component (if applicable):
6.0.2 ER2 BPMS

Expected results:
These labels of buttons should be localized and it should depends on selected language.

Additional info: