re-ordering methods in StructureBuilder
refactored replaceFluents to reduce recursion
refactored replaceFluents to reduce recursion - error corrected
refactored mergeFluentsNext to reduce recursion and cover missing cases
Corrected flipNegatedFluentNext and reduced recursion
refactored addGoalDef to cover FalseNext cases and make it more concise
remove redundant multiChildNodes at a later stage
arrow corrected to have line2 a specific distance away from endNode and line1 follow it
problem when merging a multiChildEntity (PartialOrder) resolved (partialOrder entities are left as they are even if they are the same)
fixed overlapping problem of PartialOrder nodes, fixed bug in removing redundant multiChildEntity for Fluent's false case (where immediate falseNext is a redundant multiChildEntity)
reducing overlap between fluent branches.. if there are many fluent steps, overlap will still occur (same for multiChildEntity)
added margin for goalDefinition