Added unary operators

BNF.txt

src/jrr1g18/boring/Lexer.java

src/jrr1g18/boring/Lib.java

src/jrr1g18/boring/Main.java

src/jrr1g18/boring/Parser.java

src/jrr1g18/boring/nodes/ASTNode.java

src/jrr1g18/boring/nodes/BinaryOperationNode.java

src/jrr1g18/boring/nodes/UnaryOperationNode.java

src/jrr1g18/boring/nodes/ValueNode.java

src/jrr1g18/boring/nodevisitors/Interpreter.java

src/jrr1g18/boring/nodevisitors/LISPTranslator.java

src/jrr1g18/boring/nodevisitors/NodeVisitor.java

src/jrr1g18/boring/nodevisitors/RPNTranslator.java

src/jrr1g18/boring/tokens/Token.java

test/jrr1g18/boring/test/LexerTest.java