The Omni Group has released an update to its OmniFocus applications for the iPhone and the iPad adding support for iOS 4.2 multitasking to the iPad version and introducing background sync to both versions when running on iOS 4 multitasking-capable devices. When exiting the application, OmniFocus will now complete an in-progress sync or perform an automatic sync in the background if one is scheduled to occur soon. Several improvements have also been…