lots of little fixes to English text
add label tag to data holder types for usability

When you surround a radio button and its label with the label tag, it
improves usability by providing a larger click target; clicking on the
label selects the radio button as well as clicking on the button.
Fixed translations
Merge branch '6.0.x' of https://github.com/droolsjbpm/jbpm-form-modeler into 6.0.x