-W is like -A (number of days in the future to consider, but also
specifies that we don't want special treatment at weekends.
-F changes our notion of "Friday" (the day before the weekend).
Arguably, calendar(1) is broken to have special treatment of weekends
by default, but this method maintains POLA.
o main returns int not void
o use return 0 at end of main when needed
o use braces to avoid potentially ambiguous else
o don't default to type int
o #ifdef 0 -> #if 0
Reviewed by: obrien and chuckr
E.g. for Easter, and entries like "04/SunFirst" calendar will
now report:
04/05* Good Friday (2 days before easter)
04/07* First Sunday...
instead of:
Easter-2 Good Friday...
04/SunFirst First Sunday...
I also modified the calendar files to use the variable day format
for a lot of events so that they will be reported correctly.
E.g. U.S. daylight savings time is now listed as:
04/SunFirst Daylight savings time...
There are still a lot of wrong dates in there for some events
that move from year to year, but I don't have a good calendar handy
right now that I can use for reference.