Creating multiple accepted name data wranglers can overwrite each other

[cjgrady]

If you create multiple accepted name data wranglers, for example, when aggregating occurrence data from multiple sources, that use the same name resolution service, they do not share a cache of data and the last one to write will overwrite the names file.

This happens because they are initialized at the same time and do not share a cache.

This could be solved in multiple ways.

1. Create one instance of the accepted name data wrangler and reuse it. This method would not work with factory configurations
2. Only have one instance at a time by closing (deleting via garbage collecting) before creating a new instance. This would work with factory configurations
3. Make the underlying accepted name wrangler base a singleton class. This would allow anyone writing their own code to not worry about, or even be aware, of the issue.

I think the singleton option may be the best but there may be other options or benefits to something else.