TS-1820 Unify the use of UNUSED, and eliminate trash
TS-1820 Introduce TS_UNUSED, and migrate most of the code to use either C++ style unused parameters, or this new macro
TS-1820 Fix read_manager_string(), and make sure it uses the buffer size to
ink_strlcpy().
TS-1820 Cleanup the comments some, and eliminate a few unused parameters where it was obvious