use new datespan filter in DatespanMixin
hotfix for commtrack maps
Merge pull request #965 from dimagi/cz

hotfix for commtrack maps
add fakecouch requirement
Merge pull request #966 from dimagi/requs

add fakecouch requirement
sometimes guess_type returns None
Merge pull request #967 from dimagi/mm-edge-case

sometimes guess_type returns None
only show "Use the Make New Version button" button when the button is enabled
update submodule reference to formdesigner
Merge pull request #968 from dimagi/make-new-version-info

only show "Use the Make New Version button" button when the button is en...
send less stuff back in make-a-build response
Merge pull request #969 from dimagi/trim-save-copy-response

send less stuff back in make-a-build response
Revert "Merge pull request #964 from dimagi/filter-fixin"

This reverts commit 974821f06588b4d4dcf4dcd9d6e16242406586c9, reversing
changes made to 687859e720c161c57fcd81f6346704f2b86e3743.
Merge pull request #970 from dimagi/oopsie-daisies

Revert "Merge pull request #964 from dimagi/filter-fixin"
cache worker activity reports
set the default filter expiry to 10 mins, remove dead doc string
remove unused code
Merge pull request #971 from dimagi/unused

remove unused code
Revert "Merge pull request #970 from dimagi/oopsie-daisies"

This reverts commit d010bd4cadb23e2963eab477a6fe30b7a1ba545b, reversing
changes made to 4662ed285f466e9f3675e17c87ac2b0b826aedc0.
undo undoing of yedi's changes to filter stuff...