Refactored allPreviousNodesPresentInList into areAllPresent.
Refactored isAnyNextNodePresentInList into isAnyPresent.
Adjusted tests for areAllPresent.
Fake nodes to be inserted every time there's a gap higher than one column.
Small performance improvement.
Simplified minimizing crossing logic.
Fixing several crossings in the same column to not be resolved correctly.
Merge pull request #22 from AlphaGit/refactoring-graph-dependencies

Refactoring graph dependencies