Added node type

src/main/java/tfm/exec/Main.java

src/main/java/tfm/graphs/Graph.java

src/main/java/tfm/graphs/GraphWithRootNode.java

src/main/java/tfm/graphs/augmented/ACFGBuilder.java

src/main/java/tfm/graphs/cfg/CFGBuilder.java

src/main/java/tfm/graphs/pdg/DataDependencyBuilder.java

src/main/java/tfm/graphs/pdg/PDGBuilder.java

src/main/java/tfm/graphs/sdg/SDGBuilder.java

src/main/java/tfm/nodes/AbstractTypeNodeFactory.java

src/main/java/tfm/nodes/GraphNode.java

src/main/java/tfm/nodes/IdHelper.java

src/main/java/tfm/nodes/factories/InVariableNodeFactory.java

src/main/java/tfm/nodes/factories/MethodNodeFactory.java

src/main/java/tfm/nodes/factories/NodeFactory.java

...main/java/tfm/nodes/factories/OutVariableNodeFactory.java

src/main/java/tfm/nodes/factories/StatementNodeFactory.java

src/main/java/tfm/nodes/type/NodeType.java

src/test/java/tfm/graphs/pdg/HandCraftedGraphs.java

src/test/java/tfm/graphs/pdg/PDGTests.java