tweak autotools: $(wildcard ...) plays poorly with target dist
make dist should include all files in repo
merge branch 'tweaks'
add some strays to "make dist", and install new examples Makefile
ignore autotools-generated Makefile / Makefile.in with more specificity
cp /usr/share/aclocal/pkg.m4 m4/pkg.m4, for PKG_INSTALLDIR
Merge pull request #70 from barak/tweaks

autotools tweaks