Finally have things printing to the screen

Nothing fancy yet. This commit adds a bunch of stuff (oops):

* compiling code
* VM with instructions
* remove eval.rs and just eval in the Machine struct itself
* squash most warnings now that we're using stuff here

And probably more. But that's all for now folks

Signed-off-by: Alek Ratzloff <alekratz@gmail.com>

src/syn/ast.rs

@@ -9,10 +9,12 @@ pub enum Expr {
 
 #[derive(Debug, Clone, PartialEq)]
 pub enum Atom {
+    Assign(Str),
     Word(Str),
     Float(Float),
     Int(Int),
     Str(Str),
+    Apply,
 }
 
 pub type SpAtom = Spanned<Atom>;