make sure annotations manager is on top of annotations
add Timeline button in embed mode see MapStory/mapstory/issues/878
constrain the annotations mgr MapStory/mapstory/issues/876
row editor should be on top
revert z-index changes
Revert "row editor should be on top"

This reverts commit af416273e472c5bcbb483da06c21e0a2210be58d.
make sure time slider's tooltip is below annotations tip
latest gxp to fix MapStory/mapstory/issues/880
today button should be now and use the current playback date see MapStory/mapstory/issues/848
deps - add bs4 for testing
login_required for maps view

refs mapstory/mapstory#865
deps - change to fork of django_flag for flag_type

refs mapstory/mapstory#830, mapstory/mapstory#829
annotations upload, add link to manual

refs mapstory/mapstory#874
fix absolute URLs to manual
ignore timezone in Now button as well as initial date in date picker
latest gxp see MapStory/mapstory/issues/889
change initial positioning of the manage annotations window
latest gxp see MapStory/mapstory/issues/908
latest gxp see MapStory/mapstory/issues/880
latest gxp, update threshold value, see MapStory/mapstory/issues/880