[dev-serveez] serveez binary type and guile-2.0

[Mike Gran]

Hi-

Really the only remaining Guile-2.x showstopper is the serveez binary type.

For guile-2.0 we could
- have functions that use the binary type use bytevectors instead and
  just not have serveez-binaries when compiled with guile-2.0

- reimplement the serveez-bin type to use bytevectors under the hood
  so that a serveez-bin is interchangeable with a bytevector
- or, keep the current implementation plus add functions to convert
  binary->bytevector and bytevector->binary


If the serveez-binary type is kept, one has to decide what to do with 

reference to string encodings.
- for string->binary and binary->string, we should probably assume that the
  binary is a Latin-1 encoded version of the string, and throw an error
  if the string has non-Latin-1 characters
- this would suggest adding a utf8-binary->string and string->utf8-binary
  function pair as well

Thanks,

Mike