#3 Clear input button

[Sushain Cherivirala]

Inputs to all textareas in html-tools are persisted across sessions. This can be annoying for users who manually delete all the existing input. However, not persisting the input could result in accidental loss of input in the case of a browser crash, accidentally closing the page, etc. The interface can be improved by adding a small x button or clear button to each textarea.

[Sushain Cherivirala]

Addressed in r52490, needs review.