make validation error more translator friendly, thx @jirikuncar
remove duplicate logic for active form fields, consolidate into AdminFilters
add active filters to AdminFilters
Merge branch 'master' into daterangefilter
add filter name to active filters, to match active_filter to filter_group
prevent active_filters from throwing json errors for datetime types by running clean() immediately before apply()
add comments about clean() run order
load active filters using JS and not jinja2
add logic for selected options for active filters