Update German language files to the latest changes

Strings added in release 1.5 are now translated. The posts translated
as “Billets” are now translated as “Articles” to be coherent with the
French translation of WordPress. “Single Post” is now translated
“Article Pleine-Page” to improve the comprehension.
Revert "Update German language files to the latest changes"

This reverts commit 34fae9d5940658d594d9cf1999845765e189e990.
Update French language files to the latest changes

Strings added in release 1.5 are now translated. The posts translatedas
“Billets” are now translated as “Articles” to be coherent with the
French translation of WordPress. “Single Post” is now translated
“Article Pleine-Page” to improve the comprehension.
Update French language files to the latest changes

I forgot 2 strings. Sorry.
Merge pull request #147 from EddyLB/master

Update French language files