JSON Hyper-Schema usage with Express:

* Adding capability to parse a content-type header like so:
Content-Type: application/my-media-type+json;
          profile=http://example.com/my-hyper-schema#
 * See: http://json-schema.org/latest/json-schema-core.html, section 8.1. Correlation by means of the "Content-Type" header

I want to use express as a hypermedia server, for a JSON Hyper-Schema driven API. The JSON-Schema core spec defines in section 8.1 a profile parameter, on Content-type headers; That parameter accepts a uri, including the http, "://", fqdn, and path, as well as a potential #hash-tag. This PR adds the ability for media-typer to handle this type of profile parameter. 

Without this change, media-typer would parse the following profile parameter:
```
Content-type: application/passport+json; profile=http://localhost:8080/schema/homes/home/schema.json#;
```
as:
```
profile=http
```

With this change:
```
profile=http://localhost:8080/schema/homes/home/schema.json#
```

Also, this change still successfully parses:
```
application/json; charset=utf-8; profile=http://localhost:8080/schema/homes/home/schema.json#
```
as:
```
charset=utf-8
profile=http://localhost:8080/schema/homes/home/schema.json#
```