doc/manual/fr: update "frenchle" package reference

The new version of the "frenchle" package is incompatible with
"babel".  Trying will fail with an obscure error message:

 Undefined control sequence \GOfrench
Dialogs/Settings/Panels/TrackingConfigPanel: Update hostname of DHV tracking server

Implements trac issue #3208.
Profile/TrackingProfile: Automatically migrate DHV tracking server settings
NEWS: fix misplaced entry
Dialogs/StatusPanels/SystemStatusPanel: Fix battery display
Manual de: Flattened tree to one level.
Manual de Blitz: Get buttons from one source.
Manual en: Introducing XCSoar Checklist.
Manual en: Introducing new chapter (system) integration.