[Tails-l10n] [fr] translation to review

Hey,

this is the first time I'm using git to translate Tails documentation.
Hope it won't be a mess, as usual.

commit 03f42002e814bff4bab556ada71623b87caeb768

can be found here :
http://git.immerda.ch/?p=mercedes508/tails.git;a=blobdiff;f=wiki/src/doc/first_steps/persistence/configure.fr.po;h=2b029be70ae2976e56b0a7c2e6b5331f6d9bd6dc;hp=3cc09e30dc9fc8d061fce86654a5ed5bff20f0ff;hb=03f42002e814bff4bab556ada71623b87caeb768;hpb=ad60d3e8ba244831ce9a36ee83730b040b7ed124