0.54.2.1

Fixes

• UIEditor : Fixed bugs which prevented node colour from being edited (#3383, #3384, #3385).
• Encapsulate : Fixed concurrent access to signals that could cause crashes at render time (#3381).
• Layouts : Fixed bug in editor() method (#3395).
• TBB : Fixed an obscure context management bug involving older TBB versions in custom Gaffer builds (#3409).
• NodeSetEditor : Fixed circular references for linked editors (#3421).
• Added support for loading files saved in Gaffer 0.55 (#3415). Note that because version 0.54 does not support multiple child inputs on the Parent node, only the first child input will be loaded.