make notify mails more RFC2822 conform (fixes #341 and #168)

DokuWiki now uses only one To, Ccc or Bcc header and addes additinal addresses
separated by commas. The headers are folded after each address to avoid
too long headers. The header newline was changed to CRLF (as specified in RFC).
This maybe fixes problems with some Windows Mailservers as well.

darcs-hash:20050523194316-9977f-53b03081426d0f1946b6ca4ef2e6ddb4b798e533.gz