Added admin command to update the symbols for existing currencies
Allow a list of currency codes in the initcurrencies command to limit the currencies created
Update docs
Add json file to package
Merge remote-tracking branch 'dhendo/add-symbol-updating'

* dhendo/add-symbol-updating:
  Add json file to package
  Update docs
  Added admin command to update the symbols for existing currencies
Merge remote-tracking branch 'dhendo/init-selected-currencies'

* dhendo/init-selected-currencies:
  Allow a list of currency codes in the initcurrencies command to limit the currencies created