autoconf support in CVS.

[Ryan C. Gordon]

I've jettisoned the monolithic Makefile, and replaced it with an autoconf
solution. I'll let this marinate for a day or two, and then package it up
as PhysicsFS 0.1.6. This system, once it's stable, will make it much less
painful to port to Unix-like platforms, and much more user-friendly to
build the library on such systems.

In the meantime:

Greg: Move your working copy of physfs out of the way and do a fresh
checkout. If you'll get the project files updated, I'll get those in CVS,
too. I'd also be grateful if you could see if Cygwin throws up on the
autoconf system or not.

Other people: Please try the autoconf stuff on Linux, BSD, Solaris, BeOS,
MacOS X, and anything else you can get your hands on. Thank you.

Up next: minor API additions (a means to determine last file modification
date, byte-order-safe read/write functions), Doxygen-generated manpages,
other minor tweaks, and (gasp!) a 1.0 release.

--ryan.