Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

- calendar uses cpp internally, this diff removes this usage and
substitutes a limited subset cpp processor internally.

PR: src/178463
Approved by: re (gjb)

Handle some expression regressions.
Explicitly use GNU cpp for preprocessing.
Remove explicit debugging code.
Change some variable names to be less confusing.
Improve some comments.
Improve indentation.

PR: 162211
168785
MFC after: 2 weeks

Replace hard-coded value by Julian2Gregorian converter function.

Fix typo (Pashka -> Paskha).

For calendars which don't match the solar-based Gregorian calendar,
be able to specify a year string in an entry.

On request of joel@:

- Remove the 3rd clause of the UC Berkeley copyrighted files.
- For the files added copyrighted by me, move the "All rights
reserved" to the next line.

Long awaited update to the calendar system:

- Repeating events which span multiple years (because of -A, -B or
just the three days before the end of the year).

- Support for lunar events (full moon, new moon) and solar events
(equinox and solstice, chinese new year). Because of this, the
options -U (UTC offset) and -l (longitude) are available to
compensate if reality doesn't match the calculated values.

MFC after: 1 month

Move functions which are only locally used into their C files and
make them static.

usage() in calendar.c
event_*() in io.c

PR: bin/118644
Approved by: bde@ (mentor)

style(9)ify usr.bin/calendar

PR: bin/118644
Approved by: bde@ (mentor)
MFC after: 1 week

Sort events by date.
Correct long-standing off-by-one error in -W option.

Submitted by: edwin@

Shorten some long lines. These files are still not completely
style(9) compliant.

ANSIfy function definitions.
Move some extern declarations to a header file.
Remove an unneeded extern declaration for optarg.

Include <sys/uio.h> for the complete type of struct iovec.

Approved by: das (mentor)

Add two new options:

-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.

remove __P

WARNS=2 fixup (mostly. Some are Hard To Fix(tm), so NO_WERROR is set)
Use __FBSDID().
Sort some headers.

Add missing $FreeBSD$ tags

More egcs warning fixes:
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

Allow to configure national Easter names.
Speedup my national months/days handling code.

Localize it
Handle Orthodox Eastern
-Wall cleanup

Change calendar to report the actual date for variable day events.
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.

Submitted by: pst
add forgotten file calendar.h. Sorry.