Any method routing support for Martini

A new method `Any` is introduced to route certain urls of any methods to a `martini.Handler`.

```go
// Any adds a route for any HTTP method request to the specified matching pattern.
Any(string, ...Handler)
```

With `Any` we could fully install martini upon martini, and thus other frameworks like `web.go` could be installed upon martini the same way. :)

~~~ go
package main

import (
	"github.com/Archs/martini"
	"github.com/Archs/martini-contrib/strip"
	"github.com/Archs/martini-contrib/web"
)

func main() {
	m := martini.Classic()

	m2 := martini.Classic()
	m2.Use(web.ContextWithCookieSecret(""))
	m2.Get("/", func() string {
		return "Hello World from 2nd martini"
	})

	m2.Get("/foo", func(ctx *web.Context) {
		ctx.ContentType("text/html")
		ctx.WriteString(html)
	})

	m2.Post("/foo", func() string {
		return "Welcome to Post"
	})

	m.Get("/", func() string {
		return "Hello World from 1st martini"
	})
        // Any to do the dirty tricks.
	m.Any("/2ndMartini/.*", strip.Prefix("/2ndMartini"), m2.ServeHTTP)

	m.Run()
}

const (
	html = `
	Hello Foo
<form action="foo" method="post">
	Inpu:<input type="text">
	<input type="submit" value="Submit">
</form>
`
)
~~~