Set up initioal git repo for git18-srpm.
Inhance .gitignore to ignore git-*[0-9] for local tarball review.
Update to git-1.9.0.
Update to 2.1.2.
Discard git-1.9.0 tarballs.
Discart libexecdir patch, already in upstream for git-2.1.2.
Actually discard unnecessary libdir patch file from git21.sped.
Upadate spec file for git21 packaging.
Disable 'install' option.
Add 'README' file.
Explain placeholder tarballs in git21.spec.:
Clear tarballs out of basic git repo, with .gitignore updated to match.