Get logical imports in "wren_modules" working.

There's a lot of changes here and surely some rough edges to iron out.
Also, I need to update the docs. But I want to get closer to landing
this so I can build on it.

test/api/reset_stack_after_foreign_construct.c

@@ -22,7 +22,8 @@ void resetStackAfterForeignConstructBindClass(
 void resetStackAfterForeignConstructRunTests(WrenVM* vm)
 {
   wrenEnsureSlots(vm, 1);
-  wrenGetVariable(vm, "test/api/reset_stack_after_foreign_construct", "Test", 0);
+  wrenGetVariable(vm,
+      "./test/api/reset_stack_after_foreign_construct", "Test", 0);
   WrenHandle* testClass = wrenGetSlotHandle(vm, 0);
   
   WrenHandle* callConstruct = wrenMakeCallHandle(vm, "callConstruct()");