Fix upper default critic bug.

Fix default locale to make a query with upper version.
Leaded to a bug when an unknown locale was passed to this method. Query
was .get('default') instead of .get('DEFAULT').
Fix bug with default and local.upper - Add a correct way to display the sign of the money if the locale of the user is different from the locale of the money and this locale has been overriden
Merge pull request #1 from GuillaumeCisco/fix-upper-default

Fix bugs and add correct way of displaying sign on money