- 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 r287151,r287152,r287153,r287155:

r287151:
Move common locking for filemon_inuse and struct filemon* to
filemon_pid_check().
r287152:
Remove unneeded inuse list locking in filemon_comment().
r287153:
Avoid taking proctree_lock and searching parents in wrappers if not needed.
r287155:
Fix filemon locking races.

Relnotes: yes (race fixes)
Sponsored by: EMC / Isilon Storage Division

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

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

Add the 'filemon' device. 'filemon' is a kernel module that provides a device
interface for processes to record system calls of its children.

Submitted by: Juniper Networks.