google的ceres-solver-1.13.0源文件地址：https://ceres-solver.googlesource.com/ceres-solver.gitversion:1.13.0方便没有梯子时使用。ceres-solver/ceres-solver/refs/tags/1.13.0taged7ac1a1986861b9de8b7b4bf9102b5235ee40a9taggerSameerAgarwalThuAug0300:13:592017-0700object19333b0f55c8462381038e70d42af4