We need to disable fastdev on device to prevent app hanging in the edge case described below:
1. Run any project on emulator. Check to make sure fastDev process is running.
2. Turn on fastdev property in tiapp.xml.
3. Run the same project on device.
Note: Step 1 and 2 does NOT need to be done in order (i.e: you can turn on the property before you launch the emulator, since it wouldn't make any difference). Also, note that if you run Emulator 4.2 or 4.3 in step 1, your app will crash (if run using Titanium Studio), or hang (if run using Appcelerator Studio), but the fast dev server SHOULD be running.
After step 3, you would see that the app on device hangs on splash screen. It shouldn't.
Repeat step 3 on multiple devices (2.3, 4.0, 4.1, 4.2, 4.3)