vl_getpid.c: restores Windows compatibility
vl_getpid.c: restores Windows compatibility

rxl194/vlfeat,rxl194/vlfeat,qubick/vlfeat,CansenJIANG/vlfeat,erexhepa/vlfeat,erexhepa/vlfeat,cvfish/vlfeat,rxl194/vlfeat,richarddzh/vlfeat,richarddzh/vlfeat,CansenJIANG/vlfeat,vlfeat/vlfeat,mylxiaoyi/vlfeat,mylxiaoyi/vlfeat,mylxiaoyi/vlfeat,mylxiaoyi/vlfeat,qubick/vlfeat,qubick/vlfeat,vlfeat/vlfeat,erexhepa/vlfeat,WangDequan/vlfeat,richarddzh/vlfeat,cvfish/vlfeat,erexhepa/vlfeat,richarddzh/vlfeat,rxl194/vlfeat,WangDequan/vlfeat,CansenJIANG/vlfeat,j-bo/vlfeat,vlfeat/vlfeat,cvfish/vlfeat,erexhepa/vlfeat,hongzhili/vlfeat,vlfeat/vlfeat,erexhepa/vlfeat,hongzhili/vlfeat,j-bo/vlfeat,richarddzh/vlfeat,cvfish/vlfeat,qubick/vlfeat,WangDequan/vlfeat,qubick/vlfeat,hongzhili/vlfeat,hongzhili/vlfeat,CansenJIANG/vlfeat,CansenJIANG/vlfeat,j-bo/vlfeat,WangDequan/vlfeat,cvfish/vlfeat,WangDequan/vlfeat,hongzhili/vlfeat,qubick/vlfeat,hongzhili/vlfeat,vlfeat/vlfeat,CansenJIANG/vlfeat,rxl194/vlfeat,cvfish/vlfeat,j-bo/vlfeat,vlfeat/vlfeat,richarddzh/vlfeat,mylxiaoyi/vlfeat,j-bo/vlfeat,rxl194/vlfeat,WangDequan/vlfeat,mylxiaoyi/vlfeat