Should refactor DateTime.Humanize

[MehdiK]

DateTime.Humanize has gotten a bit complex over time. It needs to be refactored.

[wahidshalaly]

I'm thinking to do the following

1. No need for two methods to show either xxxAgo() or xxxFromNow(). One method with a flag (isFuture) is enough & method should use the proper format from resources.
2. No need for two methods to show either Singlexxx() or Multiplexxx(int count). Again, one method with input (with default = 1) is enough
3. Not sure about this yet, but I'm thinking we should also refactor the DefaultFormatter
4. Split it into two formatters: DateTimeFormatter & TimeSpanFormatter
5. Shorten names by removing prefixes DateHumaniz_xxx & TimeSpanHumanize_xxx

[MehdiK]

Great ideas. This issue is however only about refactoring the implementation of DateTime.Humanize extension: the method is around 70 LoC & IMO a method over 20 lines is already too long!!

You're talking about formatters which is a different issue. So I created #102 and copied your thoughts over. I think refactoring formatters could make this method a bit cleaner but I still think we need to have much fewer if conditions and lines of code in this method.

[MehdiK]

Some love has been given to this in #106 but it still could do with more.