Fix wavpack support for MSVC9 project.
Fix wavpack support for MSVC9 project.

davel/sox,cbagwell/sox,Motiejus/sox,uklauer/sox,davel/sox,CaptainHayashi/sox,jacksonh/sox,jacksonh/sox,Distrotech/sox,mhartzel/sox_personal_fork,Motiejus/sox,Motiejus/sox,MageSlayer/sox,MageSlayer/sox,MageSlayer/sox,uklauer/sox,pcqpcq/sox,pcqpcq/sox,CaptainHayashi/sox,mhartzel/sox_personal_fork,uklauer/sox,pcqpcq/sox,cbagwell/sox,cbagwell/sox,pcqpcq/sox,mhartzel/sox_personal_fork,cbagwell/sox,CaptainHayashi/sox,uklauer/sox,davel/sox,jacksonh/sox,Motiejus/sox,jacksonh/sox,davel/sox,MageSlayer/sox,MageSlayer/sox,Distrotech/sox,Distrotech/sox,Distrotech/sox,mhartzel/sox_personal_fork,CaptainHayashi/sox