[Panel Configuration] Disallow pressing Escape whilst manipulating panel

Authored by broulik on Jun 3 2016, 9:39 AM.

Description

[Panel Configuration] Disallow pressing Escape whilst manipulating panel

When dragging the panel around and pressing Escape, we might leave the panel
in an inconsistent state, eg. somewhere in the middle of the screen.

Differential Revision: https://phabricator.kde.org/D1752