hx-disabled-elt attribute

• multiple requests with same disabled elt are handled properly12ms ‣

  this.server.respondWith('GET', '/test', 'Clicked!')
  var b1 = make('<button hx-get="/test" hx-disabled-elt="#b3">Click Me!</button>')
  var b2 = make('<button hx-get="/test" hx-disabled-elt="#b3">Click Me!</button>')
  var b3 = make('<button id="b3">Demo</button>')
  b3.hasAttribute('disabled').should.equal(false)
  b1.click()
  b3.hasAttribute('disabled').should.equal(true)
  b2.click()
  b3.hasAttribute('disabled').should.equal(true)
  // hack to make sinon process only one response
  this.server.processRequest(this.server.queue.shift())
  b3.hasAttribute('disabled').should.equal(true)
  this.server.respond()
  b3.hasAttribute('disabled').should.equal(false)