Form control (#67)

* Add Form Control

* Utility for testing control hierarchies

* Form control smoke tests

Author: mikaelho

pglet/__init__.py

@@ -8,6 +8,7 @@
 from pglet.datepicker import DatePicker
 from pglet.dialog import Dialog
 from pglet.dropdown import Dropdown
+from pglet.form import Form
 from pglet.grid import Column, Columns, Grid, Item, Items
 from pglet.html import Html
 from pglet.icon import Icon