0.4.26-2015-03-06

• Validate email, integer and url plugins initial values.
• Properly show field types "checkbox" and "radio" in the input plugin (as
  previously they showed up too large).
• It's now possible to restrict multiple usage of form handler plugins via
  allow_multiple property. In case if it's set to False, the plugin can
  be used once only (per form). Default value is True. The db_store plugin
  is from now on allowed to be used only once (per form).