Support Ruby 1.9 style attributes

[chrisrichard]

{:foo=>bar}

becomes

{foo: bar}

[Arnaud Le Blanc]

+1

note that html-style attributes are currently supported:

%p{:foo => "bar", :baz => "qux"}

becomes

%p(foo="bar" baz="qux")

[Arnaud Le Blanc]

Closed by 54df5b1