[config] remove .in files, untrack them as well
[config] remove more auto generated stuff from repository
[config] remove Makefile.in files as they are autogenerated
[config] remove local .gitignore file
[config] remove aclocal.m4 as it is locally generated
[config] add config artifacts to .gitignore
[config] re-introduce tweak.in which was wrongfully eliminated
[config] ignore aclocal.m4