Import mpc-1.0.1 to new vendor branch

This multiprecision library is required for gcc 4.6 and later.
Merge branch 'vendor/MPC'
mpc: Add DragonFly READMEs and world makefiles
Relocate libgmp and libmpfr world makefiles

This action prepares for the import of GCC 4.7 into base.
GCC 4.4, unlike GCC 4.1, requires gmp and mpfr, and these libraries
were part of the GCC 4.4 world makefile set.  GCC 4.7 also needs
these libraries, so rather than build them twice, they are moved out
to a common area where both compilers can use them.
gmp/mpfr relocation: Forgot to commit one file
ixgbe: Remove link handler tasklet remnants
ixgbe: Remove useless locking directives
Makefile.usr - Switch to pkgsrc-2012Q2.
Revert "Makefile.usr - Switch to pkgsrc-2012Q2."

This reverts commit f22a9489615d510c36982f39cd47f93d42a1c0aa.

This does not match the current batch of pkgsrc binaries.
Also, pkgsrc-2012Q3 is due out in the next 24 hours.
ixgbe: Purge queue on inactive interfaces

* The transmission code needs to process all queued packets in one way or
  another; if this is not done, the kernel will busy loop

* Fix a kernel freeze issue when bringing up network interfaces not having
  an active link (cable not plugged...)
Fix buildworld with NO_GCC41.

The Makefile logic was kinda broken and gmp/mpfr were built only when
gcc41 was being built (i.e., when NO_GCC41 was not specified).

Instead, just build them in any case.
jme: Change polling(4) support to ifpoll support

While I'm here, fix the disable/enable intr handing.
jme: Move colesce parameters setup out of sysctl tree creation
jme: Make sure only rx desc empty is cleared in status register
jme: Remove unused macros
jme: Rework MSI-X mapping, so RX MSI-X need not read register

RX empty event rarely happens (I didn't see it even if the card is
sinking full speed tiny packets on one RX ring).  Put the RX empty
events into independent MSI-X, so the hot path RX MSI-X need not
read register at all.
jme: Factor out jme_rx_restart
gcc47 build fixes: Unused-but-set-variable + more warnings

The following programs fail to build with gcc47 due to the new
unused-but-set-variable warning.  They've been fixed in various ways.
The ones set with WARNS=3 suppress cast-qual warning
There is a single enum-compare error too.

This effort is not complete.

bin/csh			pass -Wno-unused-but-set-variable
bin/mined		source file modified
bin/sh			set WARNS=3
crypto/openssh		source file modified (2)
gnu/lib/libdialog	source file modified
gnu/usr.bin/gdb/kgdb	source file modified
gnu/usr.bin/rcs 	source file modified
lib/libalias		source file modified
lib/libdevstat		source file modified
lib/libdm		set WARNS=3
lib/libevtr		source file modified
lib/libldns		pass -Wno-unused-but-set-variable
lib/libncp		source file modified
lib/libpam		set WARNS=3
lib/libsmdb		pass -Wno-unused-but-set-variable
lib/libstand		source file modified (4)
lib/libtcplay		source file modified
lib/libthread_xu	source file modified (2)
libexec/rshd		source file modified
libexec/telnetd		source file modified
libexec/ypxfr		pass -Wno-enum-compare
sbin/atm/fore_dnld	source file modified
sbin/atm/ilmid		source file modified
sbin/atm/camcontrol	source file modifief (2)
sbin/ccdconfig		source file modified
sbin/cryptdisks		source file modified
sbin/ffsinfo		source file modified
sbin/fsirand		source file modified
sbin/growfs		source file modified
sbin/hammer		source file modified
sbin/ldconfig		source file modified (real bug here?)
sbin/mount		source file modified
sbin/mount_ufs		source file modified
sbin/mount_extfs	source file modified
sbin/mountd		source file modified
sbin/natd		source file modified
sbin/newfs		source file modified
sbin/ping6		set WARNS=3, source modified
sbin/rcorder		source file modified
sbin/reboot		source file modified (real bug here?)
sbin/udevd		source file modified
sbin/usched		source file modified
sbin/vinum		source file modified
sys/boot/common 	source file modified
sys/boot/pc32/loader	source file modified
usr.bin/brandelf	source file modified
usr.bin/bzip2		pass -Wno-unused-but-set-variable
usr.bin/dfregress	source file modified
usr.bin/ee		source file modified
usr.bin/less		pass -Wno-unused-but-set-variable
Import gcc-4.7.2 to new vendor branch
Merge branch 'vendor/GCC47'