Revert "Move the location cache to the connection."

This reverts commit eb9d899edc1c4e7f5323c3fff6779abea503e8bb.

Reverting commits that tested putting the location cache into the
connection object.
Reverted to the global mutex location cache

Reverted the code to bd69f55 and then cleaned up the code to make it
easier to replace in the future.