Move *SYNC string translation out of fssync-debug

Move *SYNC string translation out of fssync-debug

Move the routines for translating ProgramType codes, and SYNC command
codes, response codes, etc out of fssync-debug, and into header files
anyone can use. These routines are useful especially for SYNC-related
debug or error logs.

Change-Id: Idc5ffe0dd798a9f18ca733e94d0bb4d740ad0836
Reviewed-on: http://gerrit.openafs.org/1390
Tested-by: Andrew Deason <adeason@sinenomine.net>
Reviewed-by: Alistair Ferguson <alistair.ferguson@mac.com>
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Tested-by: Derrick Brashear <shadow@dementia.org>