Mark client as active when leads is changed. Do not more mark client as
inactive in lead post save signal. This is alerady done in mission
post-save signal handling
More useful docstring
Indicate when client are inactives. Use smart_unicode instead of _bytes.
Use smart_unicode as well to be clean
Revert "Mark client as active when leads is changed. Do not more mark client as"

This reverts commit 62b522a3ec86257ad51518b1f6b64bdeb9c56521.
Properly mark client as avctive for new leads. Unit tests are great but
only when correct :-)
basic history loging for leads. Still sticking to admin history fwk.
Should change one day to better one.
Don't mark description as changed is content is the same (issue with
        cr/lf...)
Update translations
fix translation of unknown. Add context or more precice text