[pacman-dev] make dist targets

I tried something new today: make dist-gzip which should give us a gzipped archive of the code, perfect for the release. Not so perfect was its non-inclusion of most of our C header files, with the exception of alpm.h and alpm_list.h. If anyone is good with automake and knows what needs to be done to get the rest to be included (without exporting these headers to system include directories), go for it. -Dan