This patch drastically simplifies the device state aggegation code.
The old method was not only overly complex, but also made it impossible
to return AST_DEVICE_INVALID from the aggregation code. The unit test
update is as a result of fixing that bug.

The SIP change stems from a bug introduced by removing a DNS lookup
for hostname-based SIP channels.

(closes issue ASTERISK-16702)
Review: https://reviewboard.asterisk.org/r/1808/
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Merged revisions 358943 from http://svn.asterisk.org/svn/asterisk/branches/1.8
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Merged revisions 358944 from http://svn.asterisk.org/svn/asterisk/branches/10


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@358945 65c4cc65-6c06-0410-ace0-fbb531ad65f3