insertElement incorrect after deleteContents

[Garry Yao]

If there's a insertion happened after the selection range content is deleted, the inserted element is at the end instead of in the front.
Take the smiley plugin for reproducing:

1. Make the content and selection as below:

   		<p>te^xt</p>
   		<ul>
   			<li>te^xt</li>
   		</ul>
   
   

2. Open the smiley plugin to insert a motion;

• Expected Result:

  <p>te</p><img alt=":)" title=":)" ...><ul><li>xt</li></ul>
  

• Actual Result:

  <p>te<img alt=":)" title=":)" ...></p><ul><li>xt</li></ul>