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

Make "missing dependency" errors more useful by indicating which port
is trying to depend upon the non-existent port.

Suggested by: kris
MFC after: 3 days

An empty file does not have a positive number of lines.

Make sure that the number of lines read is non-zero before in order to
avoid dumping core.

Reported by: Wojciech A. Koszek
Pointy hat to: cperciva

Handle circular dependencies properly (via errx(3)) rather than dumping
core. This bug was made visible by a recent change to the audio/timidity++
port, which now has itself as a run dependency.

Reported by: Emil Mikulic, Andreas Klemm

Check that malloc() succeeds in makelist.

Submitted by: Roman Divacky (who did a very complete review of both
make_index.c and phttpget.c)

Add portsnap to the base system. This is a secure, easy to use,
fast, lightweight, and generally good way for users to keep their
ports trees up to date.

This is version 0.9.4 from the ports tree (sysutils/portsnap) with
the following changes:
1. The experimental pipelined http code is enabled. No seatbelts
in -CURRENT. (^_^)
2. The working directory has moved from /usr/local/portsnap to
/var/db/portsnap (as discussed on -arch two days ago).
3. Portsnap now fetches a list of mirrors (distributed as DNS SRV
records) and selects one randomly. This should help to avoid the
uneven loading which plagues the cvsup mirror network.
4. The license is now 2-clause BSD instead of 3-clause BSD.
5. Various incidental changes to make portsnap fit into the base
system's build mechanics.

X-MFC-After: 6.0-RELEASE
X-MFC-Before: 5.5-RELEASE
X-MFC-To: RELENG_6, RELENG_5, ports
discussed on: -arch and several other places
"yes please" from: simon, remko, flz, Diane Bruce
thinks this is a great idea: bsdimp
Hopes he didn't forget any files: cperciva