v0.3.0

• Removes curly braces from on-* event handler attributes.
• Handles expressions with filters like {{x | f}}
• Handles bidirectional binding to common attributes of built-in elements
• Removes curly braces from on-* event handler attributes.
• Fix <link rel='stylesheet' href='...'>
• For binding to attributes which are not properties like class, upgrades to use $ like class$="{{foo}}" to bind to the HTML attribute.
• Upgrades boolean bindings like hidden?="{{foo}}"