Fix floating point exception with cwebp -progress
Fix floating point exception with cwebp -progress

Adds a test of enc->mb_h_ to VP8IteratorProgress() to avoid a division
by zero. Fixes issue #121.

Original patch from even rouault (even dot rouault at gmail dot com).

Change-Id: Ie5fcc1821860c0a9366d5aa11f3aded4f5b98ed7

Aexyn/libwebp,altogother/webm.libwebp,Aexyn/libwebp,imazen/libwebp,rxl194/libwebp,zofuthan/libwebp,Acidburn0zzz/webm.libwebp,Distrotech/libwebp,gshORTON/webm.libwebp,comoyo/gonzo-libwebp,cysp/libwebp,Aexyn/libwebp,yohunl/libwebp,kalli123/webm.libwebp,jiehu5114/libwebp,appunite/libwebp,comoyo/gonzo-libwebp,webmproject/libwebp,gshORTON/webm.libwebp,Suvarna1488/webm.libwebp,Maria1099/webm.libwebp,gshORTON/webm.libwebp,dumganhar/libwebp,PKRoma/libwebp,ya7lelkom/libwebp,kim42083/webm.libwebp,appunite/libwebp,ttyangf/libwebp,kim42083/webm.libwebp,reimaginemedia/webm.libwebp,ericmckean/webm.libwebp,iniwf/webm.libwebp,Maria1099/webm.libwebp,kleopatra999/webm.libwebp,kalli123/webm.libwebp,imazen/libwebp,redengineer/libwebp,zofuthan/libwebp,matanbs/webm.libwebp,rxl194/libwebp,altogother/webm.libwebp,ericmckean/webm.libwebp,zofuthan/libwebp,Distrotech/libwebp,kalli123/webm.libwebp,redengineer/libwebp,rxl194/libwebp,keane83/BLE_IM,ttyangf/libwebp,jiehu5114/libwebp,reimaginemedia/webm.libwebp,abwiz0086/webm.libwebp,kleopatra999/webm.libwebp,Aexyn/libwebp,matanbs/webm.libwebp,ericmckean/webm.libwebp,altogother/webm.libwebp,zofuthan/libwebp,cysp/libwebp,comoyo/gonzo-libwebp,Suvarna1488/webm.libwebp,ya7lelkom/libwebp,webmproject/libwebp,Acidburn0zzz/webm.libwebp,ya7lelkom/libwebp,Distrotech/libwebp,abwiz0086/webm.libwebp,cysp/libwebp,appunite/libwebp,Tekserve/libwebp,comoyo/gonzo-libwebp,abwiz0086/webm.libwebp,Maria1099/webm.libwebp,PKRoma/libwebp,imazen/libwebp,webmproject/libwebp,Tekserve/libwebp,gshORTON/webm.libwebp,keane83/BLE_IM,altogother/webm.libwebp,Tekserve/libwebp,iniwf/webm.libwebp,rxl194/libwebp,jacklicn/libwebp,reimaginemedia/webm.libwebp,PKRoma/libwebp,kim42083/webm.libwebp,reimaginemedia/webm.libwebp,appunite/libwebp,altogother/webm.libwebp,appunite/libwebp,webmproject/libwebp,Maria1099/webm.libwebp,jacklicn/libwebp,comoyo/gonzo-libwebp,Acidburn0zzz/webm.libwebp,abwiz0086/webm.libwebp,ya7lelkom/libwebp,kalli123/webm.libwebp,Suvarna1488/webm.libwebp,jiehu5114/libwebp,reimaginemedia/webm.libwebp,cysp/libwebp,Aexyn/libwebp,kleopatra999/webm.libwebp,ttyangf/libwebp,yohunl/libwebp,matanbs/webm.libwebp,yohunl/libwebp,redengineer/libwebp,keane83/BLE_IM,gshORTON/webm.libwebp,Acidburn0zzz/webm.libwebp,kleopatra999/webm.libwebp,jacklicn/libwebp,ya7lelkom/libwebp,yohunl/libwebp,appunite/libwebp,Maria1099/webm.libwebp,ericmckean/webm.libwebp,comoyo/gonzo-libwebp,rxl194/libwebp,PKRoma/libwebp,abwiz0086/webm.libwebp,kleopatra999/webm.libwebp,webmproject/libwebp,redengineer/libwebp,kalli123/webm.libwebp,iniwf/webm.libwebp,jacklicn/libwebp,imazen/libwebp,dumganhar/libwebp,iniwf/webm.libwebp,kim42083/webm.libwebp,kim42083/webm.libwebp,ericmckean/webm.libwebp,redengineer/libwebp,jacklicn/libwebp,yohunl/libwebp,comoyo/gonzo-libwebp,Acidburn0zzz/webm.libwebp,imazen/libwebp,Suvarna1488/webm.libwebp,PKRoma/libwebp,ttyangf/libwebp,jiehu5114/libwebp,keane83/BLE_IM,Tekserve/libwebp,jiehu5114/libwebp,matanbs/webm.libwebp,zofuthan/libwebp,iniwf/webm.libwebp,dumganhar/libwebp,matanbs/webm.libwebp,PKRoma/libwebp,Suvarna1488/webm.libwebp,ttyangf/libwebp,keane83/BLE_IM