Overrides handling is too aggressive

Migrated issue

Reported by: jhodgdon

I have a case in the sample code where SubSample::bar() overrides Sample::bar(). The SubSample version does not have a documentation header. In parser.inc/api_shutdown(), all the documentation information (signature, code, etc.) from SubSample::bar() is being overridden by Sample::bar()'s information. This is wrong -- even though there is no documentation header, the code should remain.

I think that in general, the api_shutdown() function needs to be gone over to see what is relevant, what is working, and what isn't.