OPEN-50 Adding UNATTENDED=ON to Windows' configurations so that the viewer can...

OPEN-50 Adding UNATTENDED=ON to Windows' configurations so that the viewer can be built by all users out-of-the-box. OS Devs with full VS can switch it on if they want, however this is not needed any more for Open Source builds.

autobuild.xml

@@ -2143,6 +2143,7 @@
                 <array>
                   <string>-G</string>
                   <string>"Visual Studio 10"</string>
+                  <string>-DUNATTENDED:BOOL=ON</string>
                 </array>
               </map>
               <key>name</key>
@@ -2220,6 +2221,7 @@
                 <array>
                   <string>-G</string>
                   <string>"Visual Studio 10"</string>
+                  <string>-DUNATTENDED:BOOL=ON</string>
                 </array>
               </map>
               <key>name</key>
@@ -2296,6 +2298,7 @@
                 <array>
                   <string>-G</string>
                   <string>"Visual Studio 10"</string>
+                  <string>-DUNATTENDED:BOOL=ON</string>
                 </array>
               </map>
               <key>name</key>