Error handling for all classes uses MessageData
Refactoring duplicate codes in StructureBuilder
refactoring (grouping together MultiChildNodes)
Fixed continuously-growing actionnode by using maxWidth instead of binding to its parent's width
Refactoring visual components (Nodes) to reduce duplicates
Refactoring ActionNode
Exit node introduced for all end-of-paths, Error message for LPSFileManager changed to use toString instead of getMessage for more details