Updated French localization of TotalFinder 1.4.9

- Minor fix
Merge pull request #312 from Shade69/master

Updated French localization of TotalFinder 1.4.9
Gist Api now requires user-agent be set

Creating gists will fail with 403 if the user-agent is not set, and versions of ruby such as 1.8.7 that comes with OSX have a version of Net::HTTP that doesn't set that header by default.
Update Tabs.strings
Merge pull request #314 from NicolasSchneider/patch-1

Update Tabs.strings
French translation updated!
Merge pull request #315 from Yann-R/master

Updates to French localization of TotalFinder 1.4.9
Update readme.md
Better translations provided