small fix to koji versioning check
parameterize url path of koji build target
parameterize prefix to append to package names when looking up
small fix to bundler processor, omit version param if not specified in gemfile
attempt to determine which gem version to use when multiple versions are returned

  Uses versions retrieved from koji, git, etc to rank
  specs retrieved from rubygems.org, for variadic
  versions of a gem (ex ~>3.2)