feat(autocomplete): allow disabling asterisk on floating label

Closes #7119

Author: devversion

src/components/autocomplete/js/autocompleteDirective.js

@@ -52,6 +52,7 @@ angular
  * @param {boolean=} md-autofocus If true, the autocomplete will be automatically focused when a `$mdDialog`,
  *     `$mdBottomsheet` or `$mdSidenav`, which contains the autocomplete, is opening. <br/><br/>
  *     Also the autocomplete will immediately focus the input element.
+ * @param {boolean=} md-no-asterisk When present, asterisk will not be appended to the floating label
  * @param {boolean=} md-autoselect If true, the first item will be selected by default
  * @param {string=} md-menu-class This will be applied to the dropdown menu for styling
  * @param {string=} md-floating-label This will add a floating label to autocomplete and wrap it in
@@ -244,6 +245,7 @@ function MdAutocomplete () {
                   ng-model="$mdAutocompleteCtrl.scope.searchText"\
                   ng-keydown="$mdAutocompleteCtrl.keydown($event)"\
                   ng-blur="$mdAutocompleteCtrl.blur()"\
+                  ' + (attr.mdNoAsterisk != null ? 'md-no-asterisk="' + attr.mdNoAsterisk + '"' : '') + '\
                   ng-focus="$mdAutocompleteCtrl.focus()"\
                   aria-owns="ul-{{$mdAutocompleteCtrl.id}}"\
                   ' + (attr.mdSelectOnFocus != null ? 'md-select-on-focus=""' : '') + '\