(bug 44683) Implementing qualifiers in the JavaScript UI

Qualifiers may be added to existing claims/statements now via the JavaScript user interface.
The change set extends the claim and statement templates and adds two addition toolbar
definitions (add and remove qualifier snak) to the claimview widget.

- patch set 8: Minor code improvement

Change-Id: I236bdd0a7e9c8004a4b1a3c2eff83d690985cd05
Merge "(bug 44683) Implementing qualifiers in the JavaScript UI"