add ifNode, blockNode, assignmentNode and variableScope into the tree walker.
test ifNode
Started QL-S 2.0
Implemented QLS 2.0 syntax and AST
Fixed QL-S 2.0 outliner
Fixed QL-S 2.0 prettyprinter
Gave pages and sections names instead of idents
Removed Main.java, it is not needed anymore.
Added a Parser Factory to create an instance of the ANTLR parser, so the specific parser implementation doesn't seep through.
Added JFrame generation and MigLayout
Moved the parsing and semantic analysis of the form to a new class.
Renamed the typechecker to semantic analyser because it captures its purpose better.
Replaced \n by System.lineSeparator().
Replaced the HashMap in the InterpreterVisitor with a LinkedHashMap to retain the order in which the values are inserted.
Added a serializer to serialize form values to the csv format.
Added a TimeSource interface so the current time can be retrieved but the time can also be mocked in the tests.
Abstracted the way a filename is build.
Created a value serializer for the csv format.
Added a visitor to retrieve the file extension for a specific form of serialisation.
Implemented a persister to persist to a file.