* Remove context.Context from request.Request

This removes the context from request.Request and makes all the changes
in the code to make it compile again. It's all mechanical. It did
unearth some weirdness in that the context was kept in handler structs
which may cause havoc with concurrently handling of requests.

Fixes #2721
Signed-off-by: Miek Gieben <miek@miek.nl>

* Make test compile
Signed-off-by: Miek Gieben <miek@miek.nl>