autotools (for C impl.), change name to cm

This is a WIP, it makes much more sense to have an autotools process, makes it easier to integrate and use.

This already builds stmd, more rules are required in makefile. Advise to move deployment away from makefile "update site" doesn't belong here.

I'll do library stuff and debugging and some configure switches and whaever, if you're going to merge.

There is much work to be done on this C implementation before we can build a library and use it.

Included is rename in all places that are C to cm.
You need quotes around the variable expansion: `test "$HAVE_PERL" == no`.   You don't need quotes around `no`.  The quotes are needed to avoid barfing if, for example, `$HAVE_PERL` expands to multiple space-separated items.

I've often seen autoconf scripts be even more paranoid, with something like `test "x$HAVE_PERL" == xno`, where I think the `x` is there to avoid barfing with some `sh` implementations if `$HAVE_PERL` expands to something that looks like an option (e.g. `-n`).  I'm not sure if this is needed in any `sh` these days, however.