Explicit name of round tripper field
Explicit name of round tripper field

After more thinking I agree with the comment in commit 0debf64. It makes
more sense to explicitly name roundtripper field to keep the semantics
of "next" rountripper to handle the request clear. This is more about
behavior, not about structure.

cbugg: close bug-695

couchbaselabs/cbfs,couchbaselabs/cbfs,couchbaselabs/cbfs