title: Can't bind to 'formControl' since it isn't a known property of 'input' - Angular2 Material Autocomplete issue
body: <p>I am trying to use Angular Material <a href="https://material.angular.io/components/component/autocomplete" rel="noreferrer">Autocomplete</a> component in my Angular 2 project. I added the following to my template.</p>
  
  <pre class="lang-html prettyprint-override"><code>&lt;md-input-container&gt;
     &lt;input mdInput placeholder="Category" [mdAutocomplete]="auto" [formControl]="stateCtrl"&gt;
  &lt;/md-input-container&gt;
  
  &lt;md-autocomplete #auto="mdAutocomplete"&gt;
     &lt;md-option *ngFor="let state of filteredStates | async" [value]="state"&gt;
        {{ state }}
     &lt;/md-option&gt;
  &lt;/md-autocomplete&gt;
  </code></pre>
  
  <p>Following is my component.</p>
  
  <pre><code>import {Component, OnInit} from "@angular/core";
  import {ActivatedRoute, Router} from "@angular/router";
  import {FormControl} from "@angular/forms";
  
  @Component({
      templateUrl: './edit_item.component.html',
      styleUrls: ['./edit_item.component.scss']
  })
  export class EditItemComponent implements OnInit {
      stateCtrl: FormControl;
      states = [....some data....];
  
      constructor(private route: ActivatedRoute, private router: Router) {
          this.stateCtrl = new FormControl();
          this.filteredStates = this.stateCtrl.valueChanges.startWith(null).map(name =&gt; this.filterStates(name));
      }
      ngOnInit(): void {
      }
      filterStates(val: string) {
          return val ? this.states.filter((s) =&gt; new RegExp(val, 'gi').test(s)) : this.states;
      }
  }
  </code></pre>
  
  <p>I'm getting the following error. It looks like the <code>formControl</code> directive is not being found.</p>
  
  <blockquote>
    <p>Can't bind to 'formControl' since it isn't a known property of 'input'</p>
  </blockquote>
  
  <p>What is the issue here?</p>