Prevent duplicate tags

[Paul Everitt]

It appears possible for a user to type the same tag multiple times in the tagbox.

I don't know if this is an issue in the BE, the FE, or both. But a single user shouldn't be able to make "tag1" appear ten times.

If, though, a user Jane has tagged a resource with tag1 and user Balazs enters tag1, then the "caplet" should have its number increase by one.

[Balazs Ree (ree)]

If Balázs enters tag1 and Janet has already tagged it, beside bumping the count on the tag bubble, the tag bubble also needs to be transformed from non-deleteable to deleteable.

When later Balázs deletes the tag, it should not disappear but instead turn back to non-deleteable and get its count decreased.

[Balazs Ree (ree)]

This is now implemented correctly.

The client is never instructing the server to save the same tag twice. But it also must be assured on the server side, that in case the server receives a tagging request for a tag that the client has already tagged, the tag query adapter silently ignores the addTag call.