[pacman-dev] make dist targets

[Dan McGee]

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