[powershell mode] Integrate

Issue codemirror#3911

Author: marijnh

doc/compress.html

@@ -182,6 +182,7 @@ <h2>Script compression helper</h2>
           <option value="http://codemirror.net/mode/perl/perl.js">perl.js</option>
           <option value="http://codemirror.net/mode/php/php.js">php.js</option>
           <option value="http://codemirror.net/mode/pig/pig.js">pig.js</option>
+          <option value="http://codemirror.net/mode/powershell/powershell.js">powershell.js</option>
           <option value="http://codemirror.net/mode/properties/properties.js">properties.js</option>
           <option value="http://codemirror.net/mode/protobuf/protobuf.js">protobuf.js</option>
           <option value="http://codemirror.net/mode/python/python.js">python.js</option>

mode/index.html

@@ -103,6 +103,7 @@ <h2>Language modes</h2>
       <li><a href="asciiarmor/index.html">PGP (ASCII armor)</a></li>
       <li><a href="php/index.html">PHP</a></li>
       <li><a href="pig/index.html">Pig Latin</a></li>
+      <li><a href="powershell/index.html">PowerShell</a></li>
       <li><a href="properties/index.html">Properties files</a></li>
       <li><a href="protobuf/index.html">ProtoBuf</a></li>
       <li><a href="puppet/index.html">Puppet</a></li>

mode/meta.js

@@ -102,6 +102,7 @@
     {name: "Pig", mime: "text/x-pig", mode: "pig", ext: ["pig"]},
     {name: "Plain Text", mime: "text/plain", mode: "null", ext: ["txt", "text", "conf", "def", "list", "log"]},
     {name: "PLSQL", mime: "text/x-plsql", mode: "sql", ext: ["pls"]},
+    {name: "PowerShell", mime: "application/x-powershell", mode: "powershell"},
     {name: "Properties files", mime: "text/x-properties", mode: "properties", ext: ["properties", "ini", "in"], alias: ["ini", "properties"]},
     {name: "ProtoBuf", mime: "text/x-protobuf", mode: "protobuf", ext: ["proto"]},
     {name: "Python", mime: "text/x-python", mode: "python", ext: ["py", "pyw"]},