hyde: support trailing slashes on directories

[John Foerch]

hyde serve (hyde 0.15) fails to serve index content when the request url has a trailing slash on the end of the directory. For example, make a hyde project with a file like the following in the src/ dir:

about/index.wiki

Run hyde serve and try the following urls:

​http://localhost:8080/about/index.html → OK
​http://localhost:8080/about → OK
​http://localhost:8080/about/ → FAIL

The problem is in the procedure 'page-by-path', which is called by 'serve' to find the page object for the given uri path. In the case where the directory has a trailing slash, the path object (a list that was returned by 'uri-path') has as its last term an empty string, and page-by-path fails to deal with this.

A patch showing one way to fix this is attached.

[John Foerch]

patch to page-by-path fixing trailing-slashes handling