Marco Martin authored Mar 10, 2018 and Kurt Hindenburg committed Mar 10, 2018

Summary:
As discussed with VDG, color the scrollbar with the same colors as
the terminal color scheme itself. It looks way cleaner and modern

Test Plan: tested with several color schemes and several styles

Reviewers: #konsole, #vdg, hindenburg

Reviewed By: #konsole, #vdg, hindenburg

Subscribers: hindenburg, zzag, ngraham

Tags: #konsole

Differential Revision: https://phabricator.kde.org/D11184