test_json: Fix deprecation warnings

After a series of upgrades over recent weeks, I've discovered that
test_json.c won't compile in dev mode any more for me.

One of gcc-4.8.2, OS X Mavericks or Xcode 5 has decided to deprecate
tempnam. Which, in general, is a good thing. But for test code that just
needs a temporary file, it's just annoying.

This patch replaces usage of tempname with mkstemp, avoiding the
deprecation warning. It also removes the temporary files when the test
is complete, which apparently we weren't doing before (oops).

Review: https://reviewboard.asterisk.org/r/2957/
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Merged revisions 401872 from http://svn.asterisk.org/svn/asterisk/branches/12


git-svn-id: http://svn.asterisk.org/svn/asterisk/trunk@401873 f38db490-d61c-443f-a65b-d21fe96a405b
Blocked revisions 401391

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Blocked revisions 401379

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chan_dahdi: Fix unable to get index warning when transferring an analog call.

Transferring an analog call using flashhooks generated an unable to get
index WARNING message when the transfer is completed.

* Removed unnecessary analog subchannel shell games when transferring a
call using flashhooks.

Thanks to Tzafrir Cohen for mentioning this in a comment on issue
ASTERISK-22720.
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Merged revisions 401378 from http://svn.asterisk.org/svn/asterisk/branches/1.8


git-svn-id: http://svn.asterisk.org/svn/asterisk/trunk@401874 f38db490-d61c-443f-a65b-d21fe96a405b