Support URL fragments (by ignoring them)

[martymcguire]

Remove any URL fragment when constructing the URL path for index.

Use case: inline threaded replies could have URLs with fragments, similar to Chris Aldrich's post about threaded replies and comments with webmentions. To make sure mentions for these entries show up in the results for their page, the index path should not include the fragment (#) portion of the URL.

It'd be up to the displaying templates to extract that fragment, if any, from the mention data and make use of it to thread replies.