Place Windows build artifacts in build-vc120 rather than build-vc100.

autobuild.xml

@@ -2760,7 +2760,7 @@
         <key>windows</key>
         <map>
           <key>build_directory</key>
-          <string>build-vc100</string>
+          <string>build-vc120</string>
           <key>configurations</key>
           <map>
             <key>Debug</key>

build.sh

@@ -32,7 +32,7 @@ build_dir_Linux()
 
 build_dir_CYGWIN()
 {
-  echo build-vc100
+  echo build-vc120
 }
 
 viewer_channel_suffix()