v0.4.0

Added

• Added With trait.
• Added tbody element.
• HtmlElement: Added new attribute methods:
  • alt
  • crossorigin
  • loading
• HtmlElementRenderer: Added html getter.
• Element, HtmlElement, and TextElement now implement Clone.

Changed

• HtmlElement: Made fields pub.
• HtmlElement: Made attr method pub.
• HtmlElement: Made is_void method pub.
• TextElement: Made fields pub.
• WithChildren: Replaced children_mut with extend.
• HtmlElementRenderer: render_to_string now omits empty attributes.