MFC 272449:
Require p_cansched() for changing a process' protection status via
procctl() rather than p_cansee().
MFC 272668:
Properly set the timeout in a query_state.  The global query_timeout
configuration value is an integer count of seconds, it is not a timeval.
Using memcpy() to copy a timeval from it put garbage into the tv_usec
field.

PR:		194025
MFC 268369,268817,272771,272772:
Rewrite timeout(9) to be callout(9)-centric instead.  Move the description
of timeout(9) to the end and mark it prominently as deprecated.  Document
somewhat how times are specified for the 'sbt' variants.  Better explain
how using callout_init_*() to associate a lock with a callout resolves
common races.
MFC r273112: Set the DROP_EN bit before the RX queue is brought up and active.

He noticed issues setting this bit in SRRCTL after the queue was up,
so doing it from the sysctl handler isn't enough and may not actually
work correctly.

This commit doesn't remove the sysctl path or try to change its
behaviour.  I'll talk with others about how to finish fixing that
before I tackle that.

PR:           kern/194311
Submitted by: luigi
MFC after:    3 days
Sponsored by: Norse Corp, Inc
Merge remote-tracking branch 'freebsd/stable/10' into freebsd10