minor changes

Author: andrewseguin

src/demo-app/data-table/table-header-demo.scss

@@ -12,4 +12,4 @@
 
 .actions {
   color: rgba(0, 0, 0, 0.54);
-}
+}

src/lib/core/data-table/data-table.ts

@@ -5,7 +5,7 @@ import {
   ContentChild,
   ContentChildren,
   Directive,
-  Input, IterableChanges,
+  Input,
   QueryList,
   ViewChild,
   ViewContainerRef,
@@ -14,7 +14,6 @@ import {
 import {CollectionViewer, DataSource} from './data-source';
 import {BaseRowDef, CdkCellOutlet, CdkHeaderRowDef, CdkRowDef} from './row';
 import {CdkCellDef, CdkColumnDef, CdkHeaderCellDef} from './cell';
-import {Subject} from 'rxjs/Subject';
 import {Observable} from 'rxjs/Observable';
 import {BehaviorSubject} from 'rxjs/BehaviorSubject';
 import 'rxjs/add/operator/let';