hife the translation message
Move the logic of meta description to a template tag.
- Create a meta description template tag that generates the description string.
- Use best-practices for translation. Instead of splitting the string into smaller pieces and concatenating them, we should make only one string that takes variables.
- Included new translations for the "ar" locale.
Updated translations for other languages.
Merge branch 'meta_description' of github.com:mdebbar/alfanous

Conflicts:
	src/alfanous-django/templates/base.html