Moved assignment code to clean repository

Task C/src/visitor/CompoundExpression.java

Task C/src/visitor/CountingVariablesVisitor.java

Task C/src/visitor/EvaluationVisitor.java

Task C/src/visitor/ExpressionTest.java

Task C/src/visitor/Minus.java

Task C/src/visitor/Number.java

Task C/src/visitor/PrintVisitor.java

Task C/src/visitor/SimpleExpression.java

Task C/src/visitor/Sum.java

Task C/src/visitor/Variable.java

Task C/src/visitor/Visitor.java

Task C/src/visitor/VisitorTest.java

Task C/src/visitor/overview.png

Task C/src/visitor/overview.ucls