fixes #4110, can input text without 'value' attribute present
Fix layout on google search results.
auto merge of #4113 : payload/servo/issue-4110, r=jdm

The attribute `value` and the underlying model `TextInput` are not connected to each other, so I just pulled the value out of `TextInput`.
auto merge of #4114 : glennw/servo/table-layout-fix, r=pcwalton