[Forms] Initial minimal functionality

Initial minimal working implementation where a
two-way binding between form and form user is
observable.

Notably, change ng-options to options, since
ng-options is terminal (it breaks mct-control).

WTD-530

platform/forms/res/templates/controls/checkbox.html

@@ -0,0 +1,7 @@
+<label class="checkbox custom no-text">
+    <input type="checkbox"
+           name="{{name}}"
+           ng-model="ngModel[name]"
+           ng-disabled="ngDisabled">
+    <em>&nbsp;</em>
+</label>