Use gorilla/mux for middleware and extend

- Use gorilla/mux for middleware.
- Add Dumper, RequestID, and Logger middlewares.
- Add makeURL helper

vendor/github.com/dustin/go-humanize/humanize.go

@@ -0,0 +1,8 @@
+/*
+Package humanize converts boring ugly numbers to human-friendly strings and back.
+
+Durations can be turned into strings such as "3 days ago", numbers
+representing sizes like 82854982 into useful strings like, "83 MB" or
+"79 MiB" (whichever you prefer).
+*/
+package humanize