Do not use the date of the last RCS checkin-time as manual page data. This does not make sense anymore with git as DVCS.
* rename configure.in to configure.ac for recent autotools * require autoconf 2.68 * update obsolete macros * quote arguments to AC_../AM_.. macros * remove unneeded options --with-sbin / --with-man: --sbindir / --mandir serve exactly the same purpose