fix(chips): cursor style on static chips

Do not set the cursor style on the md-chips element if there are only static chips.
Also remove some TODO docs that have already been done.

fixes #3253. closes #4114.

src/components/chips/chips.scss

@@ -55,7 +55,10 @@ $contact-chip-name-width: rem(12) !default;
   font-size: $chip-font-size;
   padding: $chip-wrap-padding;
   vertical-align: middle;
-  cursor: text;
+
+  &:not('.md-readonly') {
+    cursor: text;
+  }
   .md-chip {
     cursor: default;
     border-radius: $chip-height / 2;

src/components/chips/js/chipsDirective.js

@@ -30,12 +30,7 @@
    *     <li>Colours for hover, press states (ripple?).</li>
    *   </ul>
    *
-   *   <ul>List Manipulation
-   *     <li>delete item via DEL or backspace keys when selected</li>
-   *   </ul>
-   *
    *   <ul>Validation
-   *     <li>de-dupe values (or support duplicates, but fix the ng-repeat duplicate key issue)</li>
    *     <li>allow a validation callback</li>
    *     <li>hilighting style for invalid chips</li>
    *   </ul>
@@ -92,7 +87,7 @@
       <md-chips-wrap\
           ng-if="!$mdChipsCtrl.readonly || $mdChipsCtrl.items.length > 0"\
           ng-keydown="$mdChipsCtrl.chipKeydown($event)"\
-          ng-class="{ \'md-focused\': $mdChipsCtrl.hasFocus() }"\
+          ng-class="{ \'md-focused\': $mdChipsCtrl.hasFocus(), \'md-readonly\': !$mdChipsCtrl.ngModelCtrl }"\
           class="md-chips">\
         <md-chip ng-repeat="$chip in $mdChipsCtrl.items"\
             index="{{$index}}"\