Added /bytes, /stream-bytes and /links endpoints

This adds the following 3 endpoints:

* /bytes/:n - takes an optional *seed* integer parameter, and returns *n* random
bytes of binary data (limited to 100KB in size).

* /stream-bytes/:n - the same as above, but streams the data.  As well as a
*seed* parameter, it accepts a *chunk_size* parameter, which determines how
many bytes are in each packet that is streamed.

* /links/:n - generates a page containing *n* links, each of which links to another
page containing those *n* links. The value of *n* is limited to 200.