Add SECURITY_CAPABILITY, SECURITY_SELINUX to deal
 with Lgetxattr() and Lsetxattr()
 use standary library syscall to get SELINUX_LABEL or
security.capability from system if the system support

 New func list
	func Lgetxattr(path string, attr string) ([]byte, error)
	func Lsetxattr(path string, attr string, data []byte, flags int)
error
	func Fgetxattr(fd uintptr, attr string) ([]byte, error)
	func Fsetxattr(fd uintptr, attr string, data []byte, flags int)
error

Signed-off-by: sndnvaps <sndnvaps@gmail.com>