cmake DBoW2 examples

alejandrofontan/AnyFeature-VSLAM CMakeLists.txt :58 

find_package(DBoW2 REQUIRED HINTS "${PROJECT_SOURCE_DIR}/Thirdparty/DBoW2/lib/cmake/DBoW2")

PeterFWS/Structure-PLP-SLAM ros/src/openvslam/CMakeLists.txt :206 

find_package(DBoW2 REQUIRED)