Felix Ernst authored Aug 01, 2019 and Nate Graham committed Aug 01, 2019

Summary:
This commit adds spacers to the kxmlgui framework so all applications
using it will be able to have any amount of spacers in their toolbar(s).

KEditToolbar gets the --- spacer --- entry by default. This entry is
modified to allow any amount of spacers to be put into the toolbars
(just like separators).
The xml scheme is updated to allow "<Spacer name="spacer_0" />" nodes
(just like separators).
KXmlGuiBuilder then builds the simple spacer by itself.

Test Plan: {F7067613}

Reviewers: dfaure, ngraham

Reviewed By: dfaure, ngraham

Subscribers: ngraham, #vdg, dfaure, kde-frameworks-devel

Tags: #frameworks

Differential Revision: https://phabricator.kde.org/D22609