Prepend files or directories containing ":" with "./" in directory

Prepend files or directories containing ":" with "./" in directory
indexes as per RFC 3986:
A path segment that contains a colon character (e.g., "this:that")
cannot be used as the first segment of a relative-path reference, as
it would be mistaken for a scheme name.  Such a segment must be
preceded by a dot-segment (e.g., "./this:that") to make a relative-
path reference.

While here add a "/" to the end of directory names, this saves us one
redirect round trip.

Found the hard way & "functionality wise, OK" ajacoutot@
RFC pointer & OK benno@