pollfish: update sdk to 4.0.0

Change-Id: I61114f05223f22eb5fd0528d5e259da19a8c6c46
web: add png favicon, ico favicon fallback for IE

Change-Id: I9a2d3c4db6a30512d3306843c2cc0c3aafb1bbbd
web: send stream if possible, fallback to loading assets as string

 * fixes the messed up favicon as we read and send it as string

Change-Id: I8997a2946f9eba02710927a10c96a3b8bc3db74d