Almost Alpha

Massive improvements across the board.

One day I'll adopt incremental commits.

examples/hello-world/main.orc

@@ -1,10 +1 @@
-import std::exit_status
-import std::conv
-import std::number
-import std::tuple
-import std::list
-
-const main := match t["set", "foo", 1] {
-  t[= "set", key, val] => 
-    $"Setting ${ key ++ $"${1 + 1}" } to ${val}"
-}
+const main := println "Hello World!" exit_status::success