- 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 282641,282658:
- Move hwpmc(4) debugging code under a new HWPMC_DEBUG option instead of
the broader DEBUG option.
- Convert hwpmc(4) debug printfs over to KTR.

Sponsored by: Norse Corp, Inc.

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

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

Add software PMC support.

New kernel events can be added at various location for sampling or counting.
This will for example allow easy system profiling whatever the processor is
with known tools like pmcstat(8).

Simultaneous usage of software PMC and hardware PMC is possible, for example
looking at the lock acquire failure, page fault while sampling on
instructions.

Sponsored by: NETASQ
MFC after: 1 month

Intel XScale hwpmc(4) support.

This brings hwpmc(4) support for 2nd and 3rd generation XScale cores.
Right now it's enabled by default to make sure we test this a bit.
When the time comes it can be disabled by default.
Tested on Gateworks boards.

A man page is coming.

Obtained from: //depot/user/rpaulo/xscalepmc/...