ticket:10 some dup detection rework

Old code works for me but fails on barista
ticket:10 more hacks

try to use atomic transaction to fix dup failures on getbarista
ticket:10 model = type(instance) instead of sender
ticket:10 more workarounds
ticket:10 add some debugging

to see what's happens on test
ticket:10 try to fix dups
ticket:5 tests rework
ticket:5 fix testcase
ticket:5 update realization and templates
ticket:5 use div instead table in form
ticket:6 update template
ticket:5 simplify views
ticket:5 fix tests
Merge branch 't5_edit' into t6_widget

Conflicts:
	apps/about/tests.py
Merge branch 't6_widget' into t8_tag

Conflicts:
	apps/about/tests.py
	apps/about/views.py
	templates/about/about_list.html
Merge branch 't8_tag' into t9_command
Merge branch 't9_command' into t10_signal

Conflicts:
	apps/about/tests.py
Merge branch 't10_signal' into t13_customer

Conflicts:
	apps/about/tests.py