Some tokens are now returned as literal tokens.
Made first parts of abstract tree. As of this commit, the tree has a few classes for statements and expressions, but they are still incomplete.
Made a few additions to the constructors of the expression classes.
Added data types to the parsing process. Not done for array types yet.
Added a few constructors to the abstract tree nodes.
Defined the Block in the grammar and added it to the function definition.
Added the Abstract Tree Node class to define which classes are tree nodes.
Made nodes for the If, ElIf, Else and While nodes of the abs tree.
Made node for the For Statement in the Tree.
Made node for the Import and ExprStat in the Tree.
Made nodes for the async, join and channel nodes.
Merge branch 'dev'