have makefile.unix clean up src/webp/*~ too
have makefile.unix clean up src/webp/*~ too

Change-Id: Ida17b92346055b197fe6ccb60a9ac223ddd46f90

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