[REM] most uses of `_model` (useless in most cases)

addons/account/models/chart_template.py

addons/mail/models/mail_thread.py

addons/mail/views/mail_templates.xml

addons/marketing_campaign/models/marketing_campaign.py

addons/resource/tests/test_resource.py

addons/web_editor/models/ir_qweb.py

addons/website_mail/controllers/main.py

addons/website_mail/views/website_mail_templates.xml

openerp/addons/base/ir/ir_http.py

openerp/addons/base/tests/test_ir_attachment.py