Add inital i18n translation support

The filter_plugin translate allows to translate strings using yavdr.mo
files from the package yavdr-i18n.

ansible-playbook must be called with an UTF-8 locale (e.g. de_DE.UTF-8), LANG=C or
LANG=POSIX are not allowed.

Usage of the new filter:

"{{ "my string" | translate }}"

group_vars/all

@@ -1,6 +1,9 @@
 ---
 # file: group_vars/all
 
+# for translation filter
+locale: "{{ ansible_env.LANG }}"
+
 # this is the standard text to put in templates
 ansible_managed_file: "*** YAVDR: ANSIBLE MANAGED FILE ***"
 branch: experimental