feat(typeahead): added subscription and unsubscribe on destroy

[krooshua]

#2382

Also fixed a bug, when navigating to another route before asyncActions() end.

TypeaheadContainerComponent.html:16 ERROR TypeError: Cannot read property 'insertNode' of undefined
    at TransitionAnimationEngine.webpackJsonp.../../../animations/@angular/animations/browser.es5.js.TransitionAnimationEngine.insertNode (browser.es5.js:3608)
    at InjectableAnimationEngine.webpackJsonp.../../../animations/@angular/animations/browser.es5.js.AnimationEngine.onInsert (browser.es5.js:4702)
    at AnimationRenderer.webpackJsonp.../../../platform-browser/@angular/platform-browser/animations.es5.js.BaseAnimationRenderer.insertBefore (animations.es5.js:387)
    at DebugRenderer2.webpackJsonp.../../../core/@angular/core.es5.js.DebugRenderer2.insertBefore (core.es5.js:13620)
    at execRenderNodeAction (core.es5.js:8886)
    at visitRenderNode (core.es5.js:8857)
    at visitSiblingRenderNodes (core.es5.js:8788)
    at visitRootRenderNodes (core.es5.js:8772)
    at renderAttachEmbeddedView (core.es5.js:9726)
    at attachEmbeddedView (core.es5.js:9606)

[valorkin]

Looks good to me