Refactored reference resolving code
cp directive implemented, tested and working
`rm` directive implemented, tested and working
Refactored code executing FSRL directives, update to 0.0.2 version
'mkd' directive implemented, documentation improved
Improved documentation
Exception is raised when trying to expand undefined variable inside a
path
Documented syntax for redefining variables into undefined state
Fixed "foo;" redefining variable to undefined
Preparations for language redesign
Tokenizer supports var/const declaration and definition, separating on
`;` character and brackets `(){}`, tokenizing comments
Tokenization of comments is better tested
Variable declarations, definitions and redefinitions are supported
once more
Constants are supported once more
Implemented `delete` keyword, updated language description
Defining variables with references to constants implemented
Defining constants with a references implemented
Implemented a guard against name-clnflicts between variables and
constants
Defining const with a reference to another const tested