HTTPTransport : avoid stopping the fire loop if one access is missing

Instead of raising an exception, log the fact we didn't know how to reached one of the required peers.
Added the missing method LoopTimer.cancel()
Added the specification of a transport implementation
Added a utility class to support filename matching

Compiles and uses a RegEx pattern to check if a string matches a "wildcard" filter
(a.k.a. filename filter), like fnmatch in Python.