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/std/hash.optimized.wat

@@ -143,7 +143,7 @@
   i32.const 16777619
   i32.mul
  )
- (func $start (; 3 ;) (type $_)
+ (func $start:std/hash (; 3 ;) (type $_)
   i32.const 0
   call $~lib/internal/hash/hashStr
   drop
@@ -196,7 +196,10 @@
   call $~lib/internal/hash/hash64
   drop
  )
- (func $null (; 4 ;) (type $_)
+ (func $start (; 4 ;) (type $_)
+  call $start:std/hash
+ )
+ (func $null (; 5 ;) (type $_)
   nop
  )
 )