Make it easier to use multiple bot processes on a single host.
Make it easier to use multiple bot processes on a single host.

Use a separate --suffix flag per python process.

TBR=csharp@chromium.org
BUG=

Review URL: https://codereview.appspot.com/117340044

luci/luci-py,luci/luci-py,luci/luci-py,luci/luci-py