Revert "Revert "optimizations meant to streamline location import""

This reverts commit 3d676d59f15f140113a937bca17757559797640d.
responses to pull request comments and bugfix to add function
display eula and cda in the context of CommCareHQ
hopefully final bugfix for LocationCache
add __repr__ to locations
Merge pull request #615 from dimagi/commtrack

urgent migration for psi commtrack
remove global uniqueness constraint on site_code
use location.path
Merge pull request #616 from dimagi/location-upload-optimize

Location upload optimize
Merge pull request #614 from dimagi/cda-eula

display eula and cda in the context of CommCareHQ
fix bug when adding member to a team and rename method
Merge pull request #617 from dimagi/add-member-bug

fix bug when adding member to a team and rename method
delete location utility command
.
make safety check logic more explicit
make resumable