Comment 2 for bug 1384979

I agree with this structure I see in the commit...

+<metadata-source-directory>
+ |-tools
+ | |-streams
+ | |-v1
+ | |-released
+ | |-proposed
+ | |-testing
+ | |-devel
+ |
+ |-images
+ |-streams
+ |-v1

since our tree only has streams/ and releases/, releases is the dir name to use in the path for the products. The old rule for 1.20.x and older is "released" purpose is in dir "releases/" when the callee passes an option to specify the agent dir and purpose, those are used in the product file and index respectively. If the generate-streams does not find the dir...it must raise an error so that someone can fix the command options or rename the dir.