ticket:8 adding test for new tag and app
ticket:8 adding implementation
Merge branch 't8_tag'
ticket:9 added tests + implementation
ticket:9 added script
Merge branch 't9_command'
ticket:10 add deltas app + tests
Merge branch 't10_signals_processor'
ticket:13 add order by priority
ticket:13 fix coverage and flake8 errors
Merge branch 't13_requests_priority'
Merge branch 'master' into t6_ajax_form_and_widget
ticket:6 add proper form validation