- Copy stable/10 (r259064) to releng/10.0 as part of the
10.0-RELEASE cycle.
- Update __FreeBSD_version [1]
- Set branch name to -RC1

[1] 10.0-CURRENT __FreeBSD_version value ended at '55', so
start releng/10.0 at '100' so the branch is started with
a value ending in zero.

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

don't assert on bad args, instead return an error..

Since so many programs don't check return value, always NUL terminate
the buf...

fix rounding when using base 1024 (the bug that started it all)...

add a set of test cases so we can make sure that things don't break
in the future...

Thanks to Clifton Royston for testing and the test program...

Approved by: re (hrs, glebius)
MFC after: 1 week

Add test-pidfile.c and increase warning level.

Add four utility functions related to struct grp processing modeled in-part
after similar calls related to struct pwd in libutil/pw_util.c:
- gr_equal()
Perform a deep comparison of two struct grp's. It does a thorough, yet
unoptimized comparison of all the members regardless of order.

- gr_make()
Create a string (see group(5)) from a struct grp.

- gr_dup()
Duplicate a struct grp. Returns a value that is a single contiguous
block of memory.

- gr_scan()
Create a struct grp from a string (as produced by gr_make()).

MFC after: 3 weeks

Add regression tests for flopen(3).

Approved by: re (blanket)

Add regression tests for trimdomain(3).