Close #138: fix a typo in the replace algorithm

dom.bs

@@ -1605,7 +1605,7 @@ steps:
    <li><p>Set <var>removedNodes</var> to a list solely containing <var>child</var>.
 
    <li><p><a>Remove</a> <var>child</var> from its <var>parent</var> with the
-   <i>suppress obvservers flag</i> set.
+   <i>suppress observers flag</i> set.
   </ol>
 
   <p class="note no-backref">The above can only be false if <var>child</var> is <var>node</var>.

dom.html

@@ -69,7 +69,7 @@
   <div class="head">
    <p data-fill-with="logo"><a class="logo" href="https://whatwg.org/"> <img alt="WHATWG" height="100" src="https://resources.whatwg.org/logo-dom.svg"> </a> </p>
    <h1 class="p-name no-ref allcaps" id="title">DOM</h1>
-   <h2 class="no-num no-toc no-ref heading settled" id="subtitle"><span class="content">Living Standard — Last Updated <time class="dt-updated" datetime="2015-12-17">17 December 2015</time></span></h2>
+   <h2 class="no-num no-toc no-ref heading settled" id="subtitle"><span class="content">Living Standard — Last Updated <time class="dt-updated" datetime="2016-01-01">1 January 2016</time></span></h2>
    <div data-fill-with="spec-metadata">
     <dl>
      <dt>Participate:
@@ -990,7 +990,7 @@ <h4 class="heading settled" data-level="4.2.1" id="mutation-algorithms"><span cl
       <li>
        <p>Set <var>removedNodes</var> to a list solely containing <var>child</var>. </p>
       <li>
-       <p><a data-link-type="dfn" href="#concept-node-remove">Remove</a> <var>child</var> from its <var>parent</var> with the <i>suppress obvservers flag</i> set. </p>
+       <p><a data-link-type="dfn" href="#concept-node-remove">Remove</a> <var>child</var> from its <var>parent</var> with the <i>suppress observers flag</i> set. </p>
      </ol>
      <p class="note no-backref" role="note">The above can only be false if <var>child</var> is <var>node</var>. </p>
     <li>Let <var>nodes</var> be <var>node</var>’s <a data-link-type="dfn" href="#concept-tree-child">children</a> if <var>node</var> is a <code class="idl"><a data-link-type="idl" href="#documentfragment">DocumentFragment</a></code> <a data-link-type="dfn" href="#concept-node">node</a>, and a list containing solely <var>node</var> otherwise.