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

tests/compiler/main.ts

@@ -1,6 +1,7 @@
 var code = 0;
 code = 1;
 
+@start
 export function main(argc: i32, argv: usize): i32 {
   return code;
 }