+ /**
+ * Basic attempt to canonicalize a URL, cleaning up some standard variants
+ * such as funny syntax or a missing path. Used internally when cleaning
+ * up URLs for storage and following redirect chains.
+ *
+ * Note that despite being on File_redirect, this function DOES NOT perform
+ * any dereferencing of redirects.
+ *
+ * @param string $in_url input URL
+ * @param string $default_scheme if given a bare link; defaults to 'http://'
+ * @return string
+ */