WEBP lib making according to https://developers.google.com/speed/webp/docs/riff_container#alpha

TODO

1. Read dimensions from "VP8 " and "VP8L" bitstreams
2. Test for chunks
3. Read ChunkHeader('ALPH') as part of ChunkHeader('ANMF')
4. ChunkHeader('ICCP') need to change data gathering loigic according to 8
5. ChunkHeader('EXIF')
6. Add ANMF and ALPH bitstreams
7. Prepare assets
   • Animated without alpha (current has alpha)
   • has ICCP color profile
   • has XMP
   • has EXIF
   • has IPTC
8. For the VP8X non-animated the "VP8 " or "VP8L" must be present - need to include this to data gathering structure

WAS DID

1. test assets
2. read Header
3. read ChunkHeader('VP8 ')chunk
4. read ChunkHeader('VP8L')chunk
5. read ChunkHeader('VP8X') extension
6. read ChunkHeader('ANIM')
7. read all ChunkHeader('ANMF')

P.S. If you have animated WEBP image with no alpha, EXIF, XMP and with ICCP color profile plz send it to voronenkotg@gmail.com