Make *filepath optionally match

[prologic]

I decided to use your library in a new project and discovered that if I have a route for /:name/tree/:ref/*path but the request path is only /foo/tree/main the route isn't matched and 404(s). I had to add an empty route for /:name/tree/:ref for things to work.

Can we make matching optional in this case? It seems logical that a *path indicate anything or nothing.

[prologic]

Good friend of mine pointed out to me that I might have been bitten by what's noted in this comment:

muxie/mux.go

Lines 18 to 20 in 0eca9f6

	// Note that since a pattern ending in a slash names a rooted subtree,
	// the pattern "/*myparam" matches all paths not matched by other registered
	// patterns, but not the URL with Path == "/", for that you would need the pattern "/".