Rework resolver (#489)

* Rework IR and resolver to use nested lookup tables
* Integrate types into IR
* Make components prefer IR, slimmed down AST
* Implement `export *`
* Add `@lazy` annotation and remove `--noTreeShaking`
* Add `@start` annotation and remove magic `main`
* Related refactoring, cleanup and docs

std/assembly/string.ts

@@ -596,6 +596,8 @@ export class String {
   }
 }
 
+export type string = String;
+
 export function parseInt(str: String, radix: i32 = 0): f64 {
   return parse<f64>(str, radix);
 }