custom safepath #150

Problem

i am not fully satisfied with how the safepath function works

solution

optimally i would like to have a way to make a safepath that does what i had with beets:

replace: {
  # remove invisible characters like null and control codes
  '[\x00-\x1f]': "",
  # remove spaces at the beginning and end
  \s+$: "",
  ^\s+: "",
  # replace path separator with similar looking unicode
  /: "⧸",
  # replace dot at the beginning with similar looking unicode
  ^\.: "․",
}

alternatively i would like to have:

• separate safepath and ASCIIization
• a safepath that doesn't care about Microsoft Windows

ideas for implementation

idea1:

• keep the current safepath as is for backwards compat
• make new functions safepathUnix safepathWindows and asciiize or normalizeUnicode that implement the alternative solution

idea2:

• a replace function with regular expressions

idea3:

• a config option that customizes what safepath does

If you want, I could try to implement idea1, idea2 or something similar.
While i have never worked with go, looking at the code it seems pretty easy with the existing code as guidance.