(bug 44283) Selenium tests for claims edit conflicts

- added tests to check edit-conflic behavior with claims
- these tests will fail as long as bug 44101 is not fixed

patchset 2: removed unrelated change
patchset 3: rebased
patchset 4: adjustement in js snippet

Change-Id: Iaa9c7fc7ec9a626b59b45e2f53c11518f9cd7bda