Part of bug 558168, set minimum Mac OS X versions per architecture ready for 64 bit builds. r=KaiRo

suite/app/macbuild/Contents/Info.plist.in

@@ -30,6 +30,13 @@
 	<true/>
         <key>LSMinimumSystemVersion</key>
         <string>10.5.0</string>
+	<key>LSMinimumSystemVersionByArchitecture</key>
+	<dict>
+		<key>i386</key>
+		<string>10.5.0</string>
+		<key>x86_64</key>
+		<string>10.6.0</string>
+        </dict>
         <key>CFBundleDocumentTypes</key>
 	<array>