Add long path awareness to the manifest.

See also #149.

guinget/My Project/app.manifest

@@ -49,10 +49,15 @@
        DPIs. Windows Presentation Foundation (WPF) applications are automatically DPI-aware and do not need 
        to opt in. Windows Forms applications targeting .NET Framework 4.6 that opt into this setting, should 
        also set the 'EnableWindowsFormsHighDpiAutoResizing' setting to 'true' in their app.config. -->
+
+  <!-- ws2:longPathAware allows using long file path support. Copied from here:
+       https://docs.microsoft.com/en-us/windows/win32/fileio/maximum-file-path-limitation?tabs=cmd
+	   The "xmlns:ws2" thing was required due to being from 2016 or it wouldn't work. -->
 
   <application xmlns="urn:schemas-microsoft-com:asm.v3">
-    <windowsSettings>
+    <windowsSettings xmlns:ws2="http://schemas.microsoft.com/SMI/2016/WindowsSettings">
       <dpiAware xmlns="http://schemas.microsoft.com/SMI/2005/WindowsSettings">true</dpiAware>
+	  <ws2:longPathAware>true</ws2:longPathAware>
     </windowsSettings>
   </application>