Feature: MS Excel (xlsx) Import/Export

Microsoft Excel files can be used to import/export devices. Several
import bugs were also fixed in the process.

Disco.Web/Views/Device/Import.cshtml

@@ -55,10 +55,16 @@
         </script>
     }
     <div id="Devices_Import_Documentation">
-        <h3>CSV Import Specification</h3>
+        <h3>XLSX/CSV Import Specification</h3>
         <h4>Format</h4>
         <ul>
-            <li>The import file must be in <strong>comma-separated values format</strong> (<a href="http://en.wikipedia.org/wiki/Comma-separated_values" target="_blank">CSV Reference</a>).</li>
+            <li>
+                The import file must be in either:
+                <ul>
+                    <li><strong>CSV (comma-separated values) format</strong> (<a href="http://en.wikipedia.org/wiki/Comma-separated_values" target="_blank">CSV Reference</a>), or</li>
+                    <li><strong>XLSX (Microsoft Excel) format</strong></li>
+                </ul>
+            </li>
             <li>Be conscious of editors removing leading zeros from serial numbers (ie: Microsoft Excel).</li>
         </ul>
         <h4>Fields</h4>