Remove $FreeBSD$: one-line sh pattern

Remove /^\s*#[#!]?\s*\$FreeBSD\$.*$\n/

bintrans: replace the quoted printable encoder/decoder

Replace the quoted printable code with one that respects RFC2045
Add tests about this parsers and encoders, using examples from the
wikipedia page.

Reviewed by: pstef
Differential Revision: https://reviews.freebsd.org/D36314

bintrans: move files to a new directory

And reflect the change in various places.