Fix data dependency

Created by: jacosro

Fixed data dependency. Now it works as before.

Changes:

• Fixed for statement data dependency generation
• Now, when a new GraphNode is created, the related ASTNode is analyzed for variables, no matter the type the ASTNode is (formerly, the ASTNode was analyzed only if it was a Statement)
• Added ASTUtils.equalsWithRange(), which compares equality between two nodes, including its ranges
• Added ASTUtils.equalsWithRangeInCU(), which compares equality between two nodes, including its ranges and its CompilationUnits
• findNodeByASTNode() now uses ASTUtils.equalsWithRangeInCU() to check for equality