additional jquery helper methods

[sollycatprint]

From @catmando on January 21, 2016 23:41

Here are a couple of handy methods we have started to use in our code, that I would like to see appear in 0.8 or 0.9:

React::Element#append_to(dom_element)  # append this element to an existing DOM element i.e.

div { "some div stuff" }.append_to(Element['.put-a-div-here'])

Element#append(ele="<div></div>", &block) 

# append an element (default an empty div) to this dom element, and 
# render the block into the appended element (if the block exists)  i.e.

Element['.add-something'].append do
  div { button { "click me" } }
end

# The first parameter (ele) is maintained so its compatible with the existing jQuery 

Element#replace_with(ele="<div></div>", &block) 
# like append but the existing element is replaced.

Copied from original issue: zetachang/react.rb#121

[catmando]

@zetachang - again a few of these might have gotten done already...