Merge test/ into tests/

review1060002

--HG--
rename : trytond/test/access.py => trytond/tests/access.py
rename : trytond/test/copy.py => trytond/tests/copy_.py
rename : trytond/test/export_data.py => trytond/tests/export_data.py
rename : trytond/test/import_data.py => trytond/tests/import_data.py
rename : trytond/test/import_data.xml => trytond/tests/import_data.xml
rename : trytond/test/model.py => trytond/tests/model.py
rename : trytond/test/mptt.py => trytond/tests/mptt.py
rename : trytond/test/sequence.xml => trytond/tests/sequence.xml
rename : trytond/test/test.py => trytond/tests/test.py
rename : trytond/test/trigger.py => trytond/tests/trigger.py
rename : trytond/test/tryton.cfg => trytond/tests/tryton.cfg
rename : trytond/test/wizard.py => trytond/tests/wizard.py
rename : trytond/test/wizard.xml => trytond/tests/wizard.xml
rename : trytond/test/workflow.py => trytond/tests/workflow.py
rename : trytond/test/workflow.xml => trytond/tests/workflow.xml
Allow customization of translation in po files

review968002
Cache.set returns the value in order to prevent using temporary variable

review543002
Fix use None instead of False in translation domain

issue3370