Tiled 1.1.5 released

The bugfixing continues in this release, to keep Tiled 1.1 from misbehaving as I try to make progress on the eventual release of Tiled 1.2. Unfortunately, one of the fixes was a regression introduced in Tiled 1.1.4. Sorry about that!

This is a companion discussion topic for the original entry at https://www.mapeditor.org/2018/04/25/tiled-1-1-5-released.html