Fix more dev-mode build issues
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Merged revisions 419129 from http://svn.asterisk.org/svn/asterisk/branches/1.8
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Merged revisions 419162 from http://svn.asterisk.org/svn/asterisk/branches/11
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Merged revisions 419163 from http://svn.asterisk.org/svn/asterisk/branches/12


git-svn-id: http://svn.asterisk.org/svn/asterisk/trunk@419175 f38db490-d61c-443f-a65b-d21fe96a405b
chan_iax2: Restore previous behavior of iax2_best_codec.

The iax2_best_codec function was changed to convert the formats
into a format compatibilities structure and grab the first
format from it. The resulting order differs from the previous
order of iax2_best_codec which causes unexpected formats to
get chosen (such as g723).

This commit brings back the old behavior of iax2_best_codec by
having a specified preference list.

Review: https://reviewboard.asterisk.org/r/3835/


git-svn-id: http://svn.asterisk.org/svn/asterisk/trunk@419180 f38db490-d61c-443f-a65b-d21fe96a405b