CMFileManager: update FR translation

The French expression "dossier racine" is the traditional way of talking
about the root folder. This also removes the ambiguity between "Root mode"
and "Root folder" for non-English-speaking people.

Update the copyright year.

cm-10.1 Change-Id: I6d34ea95b4e427421a336e11b0494da3d6bcc918

Change-Id: If3a77bdffb8111452bfa2df28b2cda20f4d1085c