Update iPad-iPhone.conf

I added support for the following iOS clients:
nPlayer ($4.99) - mp4 and xvid works. AirPlay works for mp4, but audio only for xvid.
skifta (free) - mp4 works. AirPlay works for mp4, but xvid is not working at all at this point.
TwonkyBeam (free) - mp4 works. AirPlay is not working at all, neither is xvid.

nPlayer was previously using the LG42LA644V configuration, and AirPlay was dropping to unknown renderer and failing (missing AppleCoreMedia in search string). Added multiple User-Agents to the search string and added MP4 to the StreamExtensions (among some others that were missing).