Makefile: turns on i686 optimizations for linux x86 target
Makefile: turns on i686 optimizations for linux x86 target

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