switch from hier.c to ezmlm-idx-style installer.c

[schmonz]

The ezmlm-idx installer does not hard-code every path of every binary, library, manual page, etc. to be installed. Instead, it consults data files (for instance, BIN, ETC, LIB, MAN).

Once we are free from the obligation to maintain patch compatibility with hier.c, we will have lower cost of maintenance by shifting to this kind of installation. For instance, when we add new programs, it's a data change, not a source code change. For binary packaging, it might help make systems that gzip manual pages easier to deal with.

[mbhangui]

I find ezmlm-0.53 too has this kind of installer. Look at installer.c written by djb.