- 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

Better glibc compatibility for getline/getdelim:

- Tolerate applications that pass a NULL pointer for the buffer and
claim that the capacity of the buffer is nonzero.

- If an application passes in a non-NULL buffer pointer and claims the
buffer has zero capacity, we should free (well, realloc) it
anyway. It could have been obtained from malloc(0), so failing to
free it would be a small memory leak.

MFC After: 2 weeks
Reported by: naddy
PR: ports/138320

Return -1 instead of 0 upon reaching EOF. This is somewhat ill-advised
because it means getdelim() returns -1 for both error and EOF, and
never returns 0. However, this is what the original GNU implementation
does, and POSIX inherited the bug.

Reported by: marcus@

- Add getdelim(), getline(), stpncpy(), strnlen(), wcsnlen(),
wcscasecmp(), and wcsncasecmp().
- Make some previously non-standard extensions visible
if POSIX_VISIBLE >= 200809.
- Use restrict qualifiers in stpcpy().
- Declare off_t and size_t in stdio.h.
- Bump __FreeBSD_version in case the new symbols (particularly
getline()) cause issues with ports.

Reviewed by: standards@