Outbound SIP OPTIONS messages will now include fromuser of related peer.

Outbound SIP OPTIONS messages will now include fromuser of related peer.

This behavior matches up more closely with the way invite/register/etc are handled.
This patch also modifies some adjacent code for code style compliance.  Pretty minor.

(closes issue ASTERISK-17616)
Reported by: Jeremy Kister
Patches:
     chan_sip.c-options-fromuser-fix-v1.patch uploaded by Jeremy Kister (license #6232)
........

Merged revisions 342061 from http://svn.asterisk.org/svn/asterisk/branches/1.8

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/10@342062 65c4cc65-6c06-0410-ace0-fbb531ad65f3