pktgen: Use atomic for pktgen and module reference count

Module's token is no longer needed in many places.  Ease the upcoming
changes to support multiple hardware TX queues.
gcc47: Fix plugin mechanism

There were two problems with gcc 4.7 LTO plugin:
1) It needed a number of object files from libiberty.
   Unfortunately the previous object files couldn't be used as they need
   to be built with -fPIC and libiberty is only an internal (non-pic) lib.
2) The plugin header directory was missing completely, as seen with
   gcc -print-file-name=plugin only returning "plugin".
Unbreak world (gcc47 plugin)

The installincludes target is run before "depend" target, so gtype.state
hasn't been created by the time "installincludes" is executed in stage 4.
Luckily there is a similar functionality for FILES that is executed at
the install phase, which will unbreak world (broken on previous commit).

Other headers are generated as well, so swap INCSGROUPS with FILESGROUPS
for everything to avoid having to figure which ones.  The headers are
needed at runtime, not buildtime, so this is okay.
Promote GCC 4.7 to be the default compiler

This commit causes world and kernel to be built by GCC 4.7 if the compiler
is not specified.  As a side effect, the make variable "NO_GCC47" no longer
functions.  GCC 4.7 will always be built.  In addition to changing the
default of WORLD_CCVER, the CCVER variable also defaults to "gcc47" now.

The variable "NO_GCC44" has been resurrected to prevent GCC 4.4 from
being built.  As noted in the UPDATING file, using this option is highly
discouraged.  GCC 4.4 is very useful in building some packages in pkgsrc
that fail to build with GCC 4.7's stricter standards.  The new DPorts
system is designed to use GCC 4.4 by default, regardless of the base's
default compiler setting.  If at all possible, build *both* compilers
for the maximum flexibility to build packages.
Unbreak world with NO_GCC44

gcc44 in now optional, do not require its use during buildworld
anymore.
Merge branch 'master' into gsocdrm_merger