Cleanup locales (#155)

* use localization function in formspecs

* remove unused translations

* remove F keyword from updatepo tool

* add tool readme

3d_armor/tools/README.md

@@ -0,0 +1,7 @@
+# Intllib tool
+
+please consider using the intllib tool to update locale files:
+
+```../../intllib/tools/xgettext.sh ../**/*.lua```
+
+make sure you are in `3d_armor` derectory before running this command

3d_armor/tools/updatepo.sh

@@ -12,7 +12,6 @@ xgettext --from-code=UTF-8 \
 		--keyword=S \
 		--keyword=NS:1,2 \
 		--keyword=N_ \
-		--keyword=F \
 		--add-comments='Translators:' \
 		--add-location=file \
 		-o locale/template.pot \