converters/btoa 5.2.1p0 OpenBSD

This is a port of btoa version 5.2, written by Paul Rutter, Joe Orost & Stefan Parmark. btoa converts 4 binary characters to 5 ascii ones, causing a 25% expansion. (btoa is thus more efficient than uuencode, which causes a 33% expansion.) Spaces will not be used, which should make it safe to send files over e-mail or Usenet without risking that blanks become tabs. Each resulting row of text has a single-byte checksum for error detection. A diagnosis file provides a list of errors found this way, which could then be used to retransmit only the failing lines.