issue #608 Using wildcards into shim configs

Hi there,

First of all, thanks for quick reply. I'm currently submitting my PR here since it was already implemented and (still) I think it would be of the community interest, if not now, in a near future. In any case, the plugin option will work for my particular case. 
I totally understand your worries about introducing new symbols into the config but, to be honest, I though of using an already existing symbol (*) used in maps definition. As you may see in the code, wildcards are parsed at context configuration and works as fallback for non matching mapIds when at shim.

Here I leave you the code I did for solving and adding this functionality just in case you want to reconsider it.

Thanks again and regards.