Implement FileServer rewrite API.

Implements the FileServer API proposed in
rwf2#2716 (comment).

Closes rwf2#2716.

Author: the10thWiz

core/http/src/uri/segments.rs

@@ -218,6 +218,8 @@ impl<'a> Segments<'a, Path> {
         for segment in self.clone() {
             if segment == ".." {
                 buf.pop();
+            } else if segment == "." {
+                continue;
             } else if !allow_dotfiles && segment.starts_with('.') {
                 return Err(PathError::BadStart('.'))
             } else if segment.starts_with('*') {