Accept options for git rev or condor release version
Package release tarball when appropriate

When specifying --condor-release X.Y.Z, disable git_build in the spec,
name the source tarball condor-X.Y.Z.tar.gz, and have it contain a
condor-X.Y.Z/ directory prefix.
Introduce condor_git_base_release in condor.spec

Add this macro to have separate defaults for pre-release git builds
that start with 0.x vs using actual release tarballs with a 1+ rpm
release number.
Add --rpm-base-release option to makesrpm script

Allows specifying non-default package release number