allow to configure currency (closes foodcoops#258)

config/app_config.yml.SAMPLE

@@ -39,6 +39,9 @@ default: &defaults
   #ignore_browser_locale: false
   # Default timezone, e.g. UTC, Amsterdam, Berlin, etc.
   #time_zone: Berlin
+  # Currency symbol, and whether to add a whitespace after the unit.
+  #currency_unit: €
+  #currency_space: true
 
   # price markup in percent
   price_markup: 2.0

config/initializers/currency_display.rb

@@ -0,0 +1,7 @@
+# remove all currency translations, so that we can set the default language and
+# have it shown in all other languages too
+::I18n.available_locales.each do |locale|
+  unless locale == ::I18n.default_locale
+    ::I18n.backend.store_translations(locale, number: {currency: {format: {unit: nil}}})
+  end
+end

config/locales/en.yml

@@ -450,6 +450,8 @@ en:
       contact:
         email: General contact email address, shown on website as well as some forms.
         street: Address, typically this will be your delivery and pick-up location.
+      currency_unit: Currency symbol for displaying prices.
+      currency_space: Whether to add whitespace after the currency symbol.
       homepage: Website of your foodcoop.
       help_url: Documentation website.
       applepear_url: Website where the apple and pear system for tasks is explained.
@@ -481,6 +483,8 @@ en:
         country: Country
         email: Email
         phone: Phone
+      currency_unit: Currency
+      currency_space: add space
       homepage: Homepage
       help_url: Documentation URL
       applepear_url: Apple system URL