Add disabled state for UIButton
Moved entity copying method into EntityRef, with a specific version in NetEntityRef that avoids incorrectly copying the network component.
Add binding support for 'enabled' flag in UIButton
Merge pull request #1080 from msteiger/disabled_button

Add disabled state for UIButton
Merge pull request #1081 from immortius/develop

Improved support for copying entities
Tweak at how solo-builds (Jenkins) resolve engine + engine-tests
Fixing minor issues.