Make missing strings translatable, update locale files and German (#19)

* Make a bunch of strings translatable

* Update locale files

* Update German translation

locale/signs_lib.fr.tr

@@ -1,27 +1,12 @@
 # textdomain: signs_lib
 Locked sign, owned by @1@n=Panneau verrouillé, appartient à @1@n
+Skims through all currently-loaded sign-bearing mapblocks, clears away any entities within each sign's node space, and regenerates their text entities, if any.=
+There are no signs in the currently-loaded terrain.=
+Found a total of @1 sign nodes across @2 blocks.=
+Regenerating sign entities ...=
+Finished.=
 Write=
-@1 wrote "@2" to sign at @3=
-@1 flipped the wide-font switch to "@2" at @3=
-@1 flipped the unicode-font switch to "@2" at @3=
-
-
-##### not used anymore #####
-
-locked =verrouillé 
-@1 wrote "@2" to @3sign at @4=@1 a écrit "@2" sur le panneau @3en @4
-Sign=Panneau
-Can edit all locked signs=Peut modifier les panneaux verrouillés
-Locked Sign=Panneau (verrouillé)
-green=vert
-yellow=jaune
-red=rouge
-white_red=rouge et blanc
-white_black=noir et blanc
-orange=orange
-blue=bleu
-brown=marron
-Sign (@1, metal)=Panneau (@1, métal)
-Attempt to register unknown node as fence=Tentative d'enregistrer un nœud inconnu comme barrière
-Registered @1 and @2=Enregistrement de @1 et @
-[MOD] signs loaded=[MOD] signs chargé
+Unicode font=
+Wide font=
+Wooden Wall Sign=
+Steel Wall Sign=