allow group of columns in BasicTabluarReport
remove unused import
use default arg
fix for mp3 files
Merge pull request #895 from dimagi/multimedia-audio

hotfix for mp3 files
Merge pull request #882 from dimagi/report_column_grouping

Report column grouping
use mimetypes
Merge pull request #896 from dimagi/multimedia-audio

use mimetypes
cache the user/domain/org button up top and each header tab
Merge branch 'cache-header' into realeststaging