logger: Add rotatestrategy option of 'none' which does not perform rotations

With this option in use, it may be necessary to regulate your log files
externally.

(closes issue ASTERISK-20189)
Reported by: Jaco Kroon
Patches:
    asterisk-logger-norotate-trunk.patch uploaded by Jaco Kroon (license 5671)



git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@372976 65c4cc65-6c06-0410-ace0-fbb531ad65f3