1.You must define LEVELDB_DLL in your project if you use leveldb as a dll.
2.If your windows version is lower than 6.0(windows vista),you should undefine the USE_VISTA_API micro in port_win32.h.
3.Leveldbwin may be not stable now ,so it is not suggested to use leveldbwin in your project.
4.Modification in leveldb code :
	1) including path in some headers.
	2) delete some useless platform files.