Update libwebp to 0.3.1
Update libwebp to 0.3.1

miqlas/haikuports,koletzky/haikuports,koletzky/haikuports,haikuports/haikuports,miqlas/haikuports,nielx/haikuports,haikuports/haikuports,Begasus/haikuports,haikuports/haikuports,nielx/haikuports,haikuports/haikuports,Begasus/haikuports,Begasus/haikuports,moochris/haikuports,moochris/haikuports,haikuports/haikuports,moochris/haikuports,nielx/haikuports,Begasus/haikuports,koletzky/haikuports,Begasus/haikuports,miqlas/haikuports