add test cases for myrepo.commands.{gen_repo_file,gen_rpmspec}
updated yum repo data rpm spec template
added a test case for myrepo.commands.build_repodata_srpm
added runtime dependency to rpm-build instead of packagemaker
re-introduced a member 'bdist' in myrepo.repo.Repo
fixed wrong reference to the attr
added a test case for myrepo.commands._dists_by_srpm
keep going on refactoring of myrepo.commands