- 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)

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

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

Poll bus resets on FireWire while kdb/gdb is active.

Now, it's safe to call the fwohci interrupt(polling) routine while ddb/gdb
is active. After this change, a dcons connnection over FireWire can survive
bus resets even in kernel debugger.

This means that it is not too late to plug a FireWire cable after a panic
to investigate the problem.

Actually there is a small window(between a jump to kernel from loader and
initialization of dcons_crom) in which no one can take care of a bus reset.
Except that window, firewire console should keep working
from loader to reboot even with a panic and a bus reset.
(as far as you enable LOADER_FIREWIRE_SUPPORT)

Start each of the license/copyright comments with /*-, minor shuffle of lines

- Split dcons core code and OS dependent code.
- Implement dcons_ischar() and dcons_load_buffer().
- If loader passed a dcons buffer address, keep using it.
(We still need a patch to cheat memory management system.)