Show warning if mapstraction library isn't present?

Issue Summary

I had been scratching my head as to what the problem was on one of my mapstraction-enabled sites for the past hour, and I finally found that the mapstraction library wasn't present inside the mapstraction module folder...

This, after checking the reports page, the mapstraction admin page, etc. — perhaps a check for the library could be added to the Site Reports page?

Also, it'd be awesome if the library could be included at sites/all/libraries