Verb display 'one or more' wording around language map

[ljwolford]

As per the technical call on 2/8/17: https://github.com/adlnet/lrs-conformance-test-suite/issues/129

Should eventually be edited and revisited so it's not as confusing since at least one language map is not required.

[garemoko]

https://github.com/adlnet/xAPI-Spec/blob/master/xAPI-Data.md#details-6

The human readable representation of the Verb in one or more languages. This does not have any impact on the meaning of the Statement, but serves to give a human-readable display of the meaning already determined by the chosen Verb.

The easiest change would be to drop "in one or more languages" but that's unfortunate in that it loses the concept that the verb display can be in multiple languages, which I think is important to get across. Other options of wording are problematic:

• "in multiple languages" - could be interpreted as "two or more"
• "in up to one or more languages" - sounds over complicated
• "in a non-negative number of languages" - too technical
• "in zero or more languages" - seems to be encouraging including the property when there are no languages, we we don't want to do.

Alternatively we could leave the wording as-is and include a requirement like:

* If used, the "display" property SHOULD include one or more language map.

This makes clear that it's not a MUST requirement.

[bscSCORM]

If used, the "display" property SHOULD include one or more language map.

This seems clearest.