An attempt to localise the Google and Paypal checkout buttons. 
Google always default to English it seems, at least then the sequel is in the locale (https://developers.google.com/checkout/developer/Google_Checkout_Basic_HTML_Google_Checkout_Buttons)
For Paypal when the buttons does no exits (work for fr_FR or nl_NL for instance but not fr or nl_BE, etc.), fallbacks to en_US

git-svn-id: https://svn.apache.org/repos/asf/ofbiz/trunk@1528906 13f79535-47bb-0310-9956-ffa450edef68