[FIX] properly get component reference instead of context

Before this commit, the generated code for the component directive was
using the current context as the place to look for static informations
(such as the sub components). However, it is not entirely correct, since
the current context may be different than the current component (which
is easily accessed by using the this variable).

Also, while doing this, we fix some issues in the t-set directive, which
as calling lazy values with the wrong this.

src/runtime/template_helpers.ts

@@ -108,15 +108,17 @@ function shallowEqual(l1: any[], l2: any[]): boolean {
 class LazyValue {
   fn: any;
   ctx: any;
+  component: any;
   node: any;
-  constructor(fn: any, ctx: any, node: any) {
+  constructor(fn: any, ctx: any, component: any, node: any) {
     this.fn = fn;
     this.ctx = capture(ctx);
+    this.component = component;
     this.node = node;
   }
 
   evaluate(): any {
-    return this.fn(this.ctx, this.node);
+    return this.fn.call(this.component, this.ctx, this.node);
   }
 
   toString() {