Transfers: Make Asterisk set ATTENDEDTRANSFER/BLINDTRANSFER more reliably

There were still a few cases in which ATTENDEDTRANSFER and BLINDTRANSFER
wouldn't be set on channels involved with blind and attended transfers.
This would happen with features that were initialized by channel driver
specific mechanisms in multiparty calls. This patch resolves those cases
while attempted to keep the behavior for setting those variables as
consistent as possible.

(closes issue AFS-24)
Review: https://reviewboard.asterisk.org/r/3040/
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Merged revisions 403781 from http://svn.asterisk.org/svn/asterisk/branches/12


git-svn-id: http://svn.asterisk.org/svn/asterisk/trunk@403783 f38db490-d61c-443f-a65b-d21fe96a405b
test.c: Fix too sticky unit test failed status.

Rerunning a failed unit test after loading any required modules should
allow the test to report a pass status if it now passes.
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Merged revisions 403782 from http://svn.asterisk.org/svn/asterisk/branches/12


git-svn-id: http://svn.asterisk.org/svn/asterisk/trunk@403784 f38db490-d61c-443f-a65b-d21fe96a405b