D26318: Port endl to "\n" flush at the end + use const'ref in loop

[Aleix Pol Gonzalez]

apol accepted this revision.
This revision is now accepted and ready to land.

REPOSITORY
  R266 Breeze Icons

BRANCH
  port_endl_qt5.15 (branched from master)

REVISION DETAIL
  https://phabricator.kde.org/D26318

To: mlaurent, dfaure, apol
Cc: apol, kde-frameworks-devel, LeGast00n, GB_2, michaelh, ngraham, bruns