Merge an applicable subset of r263234 from HEAD to stable/10:

Update most userspace consumers of capability.h to use capsicum.h instead.

auditdistd is not updated as I will make the change upstream and then do a
vendor import sometime in the next week or two.

Note that a significant fraction does not apply, as FreeBSD 10 doesn't
contain a Capsicumised ping, casperd, libcasper, etc. When these features
are merged, the capsicum.h change will need to be merged with them.

Sponsored by: Google, Inc.

MFC r274853:
For both iSCSI initiator and target increase socket buffer sizes before
establishing connection.

This is a workaround for Chelsio TOE driver, that does not update socket
buffer size in hardware after connection established, and unless that is
done beforehand, kernel code will stuck, attempting to send/receive full
PDU at once.

MFC r270279:

Make the iSCSI stack use __FBSDID() properly.

Sponsored by: The FreeBSD Foundation

MFC r267613 (by trasz):
Implement redirection handling in initiator.

MFC r268326:
Make iSCSI initiator keep Initiator Session ID (ISID) across reconnects.

Previously ISID was changed every time, that made impossible correct
persistent reservation, because reconnected session was identified as
completely new one.

MFC r264549:

Make it possible for the initiator side to operate in both proxy
and normal mode; this makes it possible to compile with the former
by default, but use it only when neccessary. That's especially
important for the userland part.

Sponsored by: The FreeBSD Foundation

MFC r261748:

So, it turns out SIGCHLD is discarded by default, so we have to set up
a dummy handler to make it interrupt an ioctl(2) or select(2).

This makes those short-lived iscsid(8) zombies disappear.

Sponsored by: The FreeBSD Foundation

Merge an applicable subset of r263234 from HEAD to stable/10:

Update most userspace consumers of capability.h to use capsicum.h instead.

auditdistd is not updated as I will make the change upstream and then do a
vendor import sometime in the next week or two.

Note that a significant fraction does not apply, as FreeBSD 10 doesn't
contain a Capsicumised ping, casperd, libcasper, etc. When these features
are merged, the capsicum.h change will need to be merged with them.

Sponsored by: Google, Inc.

MFC r274853:
For both iSCSI initiator and target increase socket buffer sizes before
establishing connection.

This is a workaround for Chelsio TOE driver, that does not update socket
buffer size in hardware after connection established, and unless that is
done beforehand, kernel code will stuck, attempting to send/receive full
PDU at once.

MFC r270279:

Make the iSCSI stack use __FBSDID() properly.

Sponsored by: The FreeBSD Foundation

MFC r267613 (by trasz):
Implement redirection handling in initiator.

MFC r268326:
Make iSCSI initiator keep Initiator Session ID (ISID) across reconnects.

Previously ISID was changed every time, that made impossible correct
persistent reservation, because reconnected session was identified as
completely new one.

MFC r264549:

Make it possible for the initiator side to operate in both proxy
and normal mode; this makes it possible to compile with the former
by default, but use it only when neccessary. That's especially
important for the userland part.

Sponsored by: The FreeBSD Foundation

MFC r261748:

So, it turns out SIGCHLD is discarded by default, so we have to set up
a dummy handler to make it interrupt an ioctl(2) or select(2).

This makes those short-lived iscsid(8) zombies disappear.

Sponsored by: The FreeBSD Foundation