internationalize dates

[ghost]

The format of the dates is not translated yet. To change this i looked into the code and thought a bit about it and came up with the following todos:

• set locales for moment.js (@hql287 saw you already did this, not sure yet if it is globally available this way, will check)
• refactor form field "Settings -> Invoice -> Other -> Date Format" options
• use locale for form field "Create A New Invoice -> Due Date" format

Anything else to consider?

Would add a pull request for this feature ... ok?

[hql287]

Wait, what's your question again? 😅

[ghost]

I updated the issue description and marked the questions :laughing: better? :see_no_evil:

[ghost]

Saw that the correct moment.js locale is available everywhere. But some more formats in the "Settings -> Invoice -> Other -> Date Format" field are still missing. I send a PR for this ...

[ghost]

Closing here ... continued in #247