New default character conversion wrt NOT hexencoding '/'

New default character conversion wrt NOT hexencoding '/'
* '/' is just translated to ':'
* by default CAP encodings of existing files is not decoded but used as is
* this means eg folders created in Netalk 2.2.x named "my/folder" which
  were saved as "my:2ffolder" on the server with Netatalk 3.y will
  appear as "my:2ffolder"
* uniconv can be used to convert the CAP encoding