Inaccurate position of outline text with SFML back-end

[cschreib]

In the current latest version of SFML (2.5.1) there is a bug in outline glyph rendering which makes the outline sometimes inaccurate. This is normally fine for regular fonts, but significant for italic of bold. In some regular fonts, certain characters like : or + also have their outline incorrectly positioned. I have opened a PR to fix this in SFML SFML/SFML#1827. When this PR is merged, or if using a custom build of SFML, the outline can be fixed to the right position by defining SFML_HAS_OUTLINE_GLYPH_FIX when building lxgui.

[cschreib]

This has been merged upstream and should be available in SFML 2.6.0.