Improvement: InputFields in Backend ignore ShopCurrency configuration

[MLindenhofer]

If there are configurations for ShopCurrency like this:

SilverShop\ORM\FieldType\ShopCurrency:
  decimal_delimiter: '.'
  thousand_delimiter: ','
  currency_symbol: '€'
  # european style currencies, e.g. 45,00 € instead of €45,00
  append_symbol: true

They will only affect the output in frontend. But in Backend the input still sticks with the default config with the english $ currency and the delimiters.

Example: Apply 5,10 for Specific Price with the config from above this will be converted and shown as 5.100 in Frontend because the comma is still evaluated as a thousands delimiter although . was defined for this in the config.

There is progress to improve internationalisation stuff in silvershop-core:
silvershop/silvershop-core#818 (comment)

Would be great if this module will also be improved :) to create a better experience for international e-commercers

Best regards