- Copy stable/10@296371 to releng/10.3 in preparation for 10.3-RC1
builds.
- Update newvers.sh to reflect RC1.
- Update __FreeBSD_version to reflect 10.3.
- Update default pkg(8) configuration to use the quarterly branch.

Approved by: re (implicit)

MFC r292013:

Use stdint.h instead of inttypes.h as the latter pollutes namespace more

Submitted by: bde
Sponsored by: EMC / Isilon Storage Division

MFC r292004:

Fix compilation when -DDEBUG is defined by adding inttypes.h #include
for intmax_t

Differential Revision: https://reviews.freebsd.org/D4434
Reported by: cppcheck
Reviewed by: jhb
Sponsored by: EMC / Isilon Storage Division

MFC 281887:
Reassign copyright statements on several files from Advanced
Computing Technologies LLC to Hudson River Trading LLC.

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

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

Add an implementation of open_memstream() and open_wmemstream(). These
routines provide write-only stdio FILE objects that store their data in a
dynamically allocated buffer. They are a string builder interface somewhat
akin to a completely dynamic sbuf.

Reviewed by: bde, jilles (earlier versions)
MFC after: 1 month