Makefile enhancements and a new manual page

Hi Richard,

I wanted to share with you some of the additions I made for packaging with Debian, in the hope that they are useful to you too.

I've written up a small manpage, added rules to the Makefile to install/uninstall it, and amended the Makefile to allow users or external utilities such as Debian's packaging systems to add their own compiler, preprocessor, and linker flags.

Let me know if you'd prefer smaller patches with just a subset of these changes. Cheers,

Felix

PS - On a silly bureaucratic note, is it time for a minor version number bump? It would solve some odd policy questions on version numbering for Debian...