[Feature Request] Add date format options in settings

[inson1]

It would be great to set your favorite format. I like for example DD-MM-YYYY

date format in the history view date format in the Converter in Currency

Thank you :)

[Yet-Zio]

@inson1 By calender format option, I assume you meant the date format in the history view. If so, I will surely add it in the future.

[inson1]

@Yet-Zio No I meant in Converter in Currency, but this would be also great! - issue name/info edited

[Yet-Zio]

Added as of #91