Initial-checkin for ON2 Software AVC/H264 decoder

o when neon is present, the performance gain of On2 AVC software decoder
  over PV software decoder is more than 30%.

o In addition, it fixes some known PV software decoder issues like missing
  output frames

o allow both pv and on2 software avc to be available for easy comparision

o change output frames from 8 to 16

Change-Id: I567ad1842025ead7092f0c47e3513d6d9ca232dd