[MKDoc-dev] [BUG] [1.6] TimeRange dates should be displayed better

[Bruno Postle]

Currently, if a TimeRange component is addded to a document, it 
displays something like this:

  Party for 9-12 years olds
    Starts December 18, 2005 14:30
    Ends December 18, 2005 16:30

When the event then appears in the Headlines component it displays 
like so:

  Festive fun
    Party for 9-12 years olds
    From: December 18, 2005 at 14:30 To: December 18, 2005 at 16:30

Aside from the slight difference where one says "Starts", "Ends" and 
the other says "From:, at", "To:, at", the datelines are far too 
noisy.

It should be cleaner:

  From 14:30 to 16:30 December 18 2005

..or when it spans more than one day:

  From 12:00 January 18, to 17:00 February 02 2005

It should only show the long form when the event spans more than 
one year:

  From 19:00 December 31 2004, to 04:00 January 01 2005.

To do this we need smoe new methods for flo::editor::TimeRange, so 
each of the three forms can be templated separately:

  same_day()
  same_year_different_day()
  different_year()

-- 
Bruno