Remove environs/tools.FindInstanceTools
Merge pull request #649 from axw/remove-environs-tools-findinstancetools

Remove environs/tools.FindInstanceTools

Reduce surface area of environs/tools as we reduce reliance on it. Eventually the simplestreams parts should be relocated and become client-side, import-only. Several users do not need to be using FindInstanceTools (use FindExactTools or just FindTools instead).