status deletes, profile updates (#30)

1. Proper DELETE of federated statuses (not yet deleting all the media and stuff -- i still have to implement this -- but the actual status is toast).
2. Proper UPDATE of profiles. When you change your profile picture on your remote instance, that will now register properly in GoToSocial.
3. Scrolling down the home timeline - it no longer just sort of ends, and will keep loading older statuses as you scroll.
4. Little bugfixes -- still had some nil pointer errors when dereferencing remote accounts.

internal/util/uri.go

@@ -232,3 +232,25 @@ func ParseOutboxPath(id *url.URL) (username string, err error) {
 	username = matches[1]
 	return
 }
+
+// ParseFollowersPath returns the username from a path such as /users/example_username/followers
+func ParseFollowersPath(id *url.URL) (username string, err error) {
+	matches := followersPathRegex.FindStringSubmatch(id.Path)
+	if len(matches) != 2 {
+		err = fmt.Errorf("expected 2 matches but matches length was %d", len(matches))
+		return
+	}
+	username = matches[1]
+	return
+}
+
+// ParseFollowingPath returns the username from a path such as /users/example_username/following
+func ParseFollowingPath(id *url.URL) (username string, err error) {
+	matches := followingPathRegex.FindStringSubmatch(id.Path)
+	if len(matches) != 2 {
+		err = fmt.Errorf("expected 2 matches but matches length was %d", len(matches))
+		return
+	}
+	username = matches[1]
+	return
+}