I was coding earlier this week, but my brain was so foggy I ended up not
knowing what I was doing. After a few days break, I've cleaned up the
mess, which took hours.
Changes:
* Variables can be assigned
* Added new value types as placeholders
* Added 'compare' and 'assign' to the AST
* Added duplicate opcode
* Added functions to copy and free values
* Max name length is 255 chars
* Compound assigns are squeezed into one word
To be completed:
* Tests for this commit's changes
* Compound assignments
* Variable access
