sys: Remove ancient SCCS tags.

Remove ancient SCCS tags from the tree, automated scripting, with two
minor fixup to keep things compiling. All the common forms in the tree
were removed with a perl script.

Sponsored by: Netflix

sys: Remove $FreeBSD$: one-line .h pattern

Remove /^\s*\*+\s*\$FreeBSD\$.*$\n/

Fix flags collision causing inability to enable CBQ in ALTQ

The CBQ BORROW flag conflicts with the RMCF_CODEL flag; the
two sets of definitions actually define the same things. The symptom
is that a kernel with CBQ support and not CODEL fails to load a QoS
policy with the obscure error "pfctl: DIOCADDALTQ: Cannot allocate memory."
If ALTQ_DEBUG is enabled, the error becomes a little clearer:
"rmc_newclass: CODEL not configured for CBQ!" is printed by the kernel.
There really shouldn't be two sets of macros that have to be defined
consistently, but the include structure isn't right for exporting
CBQ flags to altq_rmclass.h. Re-align the definitions, and add
CTASSERTs in the kernel to ensure that the definitions are consistent.

PR: 215716
Reviewed by: pkelsey
MFC after: 2 weeks
Sponsored by: Forcepoint LLC
Differential Revision: https://reviews.freebsd.org/D17758

Remove register keyword from sys/ and ANSIfy prototypes

A long long time ago the register keyword told the compiler to store
the corresponding variable in a CPU register, but it is not relevant
for any compiler used in the FreeBSD world today.

ANSIfy related prototypes while here.

Reviewed by: cem, jhb
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D10193

sys/net*: minor spelling fixes.

No functional change.

Add ALTQ(9) support for the CoDel algorithm.

CoDel is a parameterless queue discipline that handles variable bandwidth
and RTT.

It can be used as the single queue discipline on an interface or as a sub
discipline of existing queue disciplines such as PRIQ, CBQ, HFSC, FAIRQ.

Differential Revision: https://reviews.freebsd.org/D3272
Reviewd by: rpaulo, gnn (previous version)
Obtained from: pfSense
Sponsored by: Rubicon Communications (Netgate)

Move ALTQ from contrib to net/altq. The ALTQ code is for many years
discontinued by its initial authors. In FreeBSD the code was already
slightly edited during the pf(4) SMP project. It is about to be edited
more in the projects/ifnet. Moving out of contrib also allows to remove
several hacks to the make glue.

Reviewed by: net@