(bug 44014) Handling of changed data types

UI will no longer fail after a mismatch between Snak's value's data value type and Snak's
property's data type's data value type because of some internal changes or change of an used
property.

- patch set 3: Updated messages
- patch set 4: Updated css classes

Depends on DataValue's Ib441d70a

Change-Id: I0c3bfa2dea8409d09d164fe6dc2257f06118bdce
Merge "(bug 44014) Handling of changed data types"