localtime: Fix file descriptor leak on kqueue(2) systems

The localtime management in the Asterisk core contains a thread that watches
for changes in the local timezone. On systems where the directory containing
/etc/localtime is modified frequently, the thread monitoring the changes will
be woken up to determine if any changes in timezone have occurred. When using
kqueue(2), this can cause a leak of file descriptors due to some improper
management of resources.

This patch updates the kqueue(2) handling in localtime, such that is no longer
leaks resources.

Review: https://reviewboard.asterisk.org/r/4450/

ASTERISK-24739 #close
Reported by: Ed Hynan
patches:
  11.15.0-u.diff uploaded by Ed Hynan (Licnese 6680)
  11.7.0-u.diff uploaded by Ed Hynan (License 6680)
  svn-trunk-Jan-26-2015-u.diff uploaded by Ed Hynan (License 6680)
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Merged revisions 432691 from http://svn.asterisk.org/svn/asterisk/branches/11
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Merged revisions 432693 from http://svn.asterisk.org/svn/asterisk/branches/13


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@432694 65c4cc65-6c06-0410-ace0-fbb531ad65f3