Changeset 10520 for trunk/sources/HeuristicLab.Encodings.SymbolicExpressionTreeEncoding/3.4/Interfaces

#2076: Got rid of layout adapters. Extracted the previous drawing code and made it into another layout engine called the BoxesLayoutEngine (because it divides the areas necessary for each subtree into boxes and recursively applies the layout). Simplified usage of layout engine so that most of the things are handled internally, and the user just has to provide some lambdas telling the engine how to navigate the original tree. Added context option in the SymbolicExpressionTreeChart to choose which layout engine to use for tree drawing. Moved the SymbolicExpressionTreeLatexFormatter to the HeuristicLab.Encodings.SymbolicExpressionTreeEncoding.Views assembly because it depends on the layout engine.