Rename archivalrouter.MatchRegex -> archivalrouter.Route, supporting regex/prefix matching
add redir_to_exact to turn off redirect to exact timestamp in RewritingReplayHandler
update README
currently MatchPrefix and MatchRegex. handler returns a single response
(no chaining for now)
* rewriting: don't rewrite anchor only urls
* perf: add a very basic profiler in WBHandler for testing