Replaced toggleClass with add/removeClass where appropriate

[WebsiteDeveloper]

Partial fix for #3338

[peterflynn]

It looks like this is implementing 'option A' from #3338, which is the most verbose of all the approaches. Any interest in looking into the cleaner options B or C?

[WebsiteDeveloper]

i did look at B and C. For me B seems the best for compatibility but i thought if this is decided a little later we could first merge this and maybe after that still change those places to use an utility function.

[peterflynn]

I think it would be a lot easier to do that cleanup now, rather than going through later and trying to identify addClass()/removeClass() pairs to migrate over.

[WebsiteDeveloper]

You are right, actually it would be fairly easy because all show up in this requests diff, but if you think it's better then i'll just add an utility function.

[WebsiteDeveloper]

@peterflynn i added an util function, so i basically implemented option B.

[peterflynn]

This condition got inverted

[peterflynn]

@WebsiteDeveloper done reviewing

[WebsiteDeveloper]

@peterflynn fixes pushed.

[peterflynn]

Thanks @WebsiteDeveloper! Merging now.