Remove /guides/environment.markdown, change all relevant links
Remove /guides/configuring.markdown, and change links

This page is superseded by a cluster of pages in the versioned PRM. Instead of
leaving it to rot, we should axe it and accept the temporary pain of putting
links to new docs into old docs.
Merge pull request #361 from nfagerlund/aug_2014_remove_guides

Remove two guides and change all relevant links