- Copy stable/10 (r259064) to releng/10.0 as part of the
10.0-RELEASE cycle.
- Update __FreeBSD_version [1]
- Set branch name to -RC1

[1] 10.0-CURRENT __FreeBSD_version value ended at '55', so
start releng/10.0 at '100' so the branch is started with
a value ending in zero.

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

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

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

Fix return value of function.

Submitted by: Dan McGregor <dan dot mcgregor at usask dot ca>

The 10GBASE-T card should use an IPG of 1. Also enable the check
for low power startup on this card.

cxgb(4) updates, including:
- support for the new Gen-2, BT, and LP-CR cards.
- T3 firmware 7.7.0
- shared "common code" updates.

Approved by: gnn (mentor)
Obtained from: Chelsio
MFC after: 1 month