[MERGE][0.16?] Normalise URLs in RemoteHTTPTransport

[Robert Collins]

Robert Collins has voted +1.
Status is now: Approved
Comment:
Please merge this to .dev, I'll pull to 0.16rc2 from there. Can you 
please also work up a stricter version that enforces normalisation for 
.base on all transports? (URL comparisons should be done in normalised 
form is the base issue here)

For details, see: 
http://bundlebuggy.aaronbentley.com/request/%3C20070427055700.GM17953%40steerpike.home.puzzling.org%3E