Fix #64166: quoted-printable-encode stream filter incorrectly discarding whitespace

If trailing whitespace on a line is detected, mark the linebreak as a
soft linebreak.
Fix #64166: quoted-printable-encode stream filter incorrectly discarding whitespace

Second attempt: need to use lookaheadto determine whether to encode ws
trailing ws
Move unsigned char declaration to top of block
add more tests for bug #64166
Merge branch 'PHP-5.4' into PHP-5.5

* PHP-5.4:
  add more tests for bug #64166
  Move unsigned char declaration to top of block
  trailing ws
  Fix #64166: quoted-printable-encode stream filter incorrectly discarding whitespace
  Fix #64166: quoted-printable-encode stream filter incorrectly discarding whitespace
news for #64166
Merge branch 'PHP-5.4' into PHP-5.5

* PHP-5.4:
  news for #64166
update NEWS