Hide the Add link and Remove button if set to null

Tab array updated to behave the same as arrays where the Add link and
Remove button are hidden if set to null

Author: joelwkent

src/tabarray.html

@@ -15,7 +15,7 @@
           ng-class="{active: selected.tab === $index}">
           <a href="#">{{interp(form.title,{'$index':$index, value: item}) || $index}}</a>
       </li>
-      <li ng-hide="form.readonly"
+      <li ng-hide="form.readonly || form.add === null"
           ng-disabled="form.schema.maxItems <= modelArray.length"
           ng-click="$event.preventDefault() || (selected.tab = appendToArray().length - 1)">
         <a href="#">
@@ -36,7 +36,7 @@
 
            <div schema-form-array-items></div>
 
-           <button ng-hide="form.readonly"
+           <button ng-hide="form.readonly || form.remove === null"
                    ng-click="selected.tab = deleteFromArray($index).length - 1"
                    ng-disabled="form.schema.minItems >= modelArray.length"
                    type="button"
@@ -60,7 +60,7 @@
           ng-class="{active: selected.tab === $index}">
           <a href="#">{{interp(form.title,{'$index':$index, value: item}) || $index}}</a>
       </li>
-      <li ng-hide="form.readonly"
+      <li ng-hide="form.readonly || form.add === null"
           ng-disabled="form.schema.maxItems <= modelArray.length"
           ng-click="$event.preventDefault() || (selected.tab = appendToArray().length - 1)">
         <a href="#">