gddo-server: add search results and referer to logging.

Log a list of package served to learn what user goes to when searching.
Log referer to learn where does user come from, such as Google search,
github reference link, etc.
Remove unnecessary handler and response writer wrapper since both are
handled by GAE request log.

This fixes golang/gddo#390.

Change-Id: I7ac049ad7723edb229cea0dc8d0c64295981d368
Reviewed-by: Andrew Gerrand <>
2 files changed