* fixed heading atan2 problem

* refined quality of filtering measurement candidates

* fixed some comment problmes

* fixed filtering measurement processure

Planning: allow empty st_graph_boundary; do not return error when no mapping of obstacle. abstract redundant code to seperate function.

* filter nan points, and fix a bug of hdmap_input

* set the log level to 3

Fix coding style with find . -iname *.h -o -iname *.cc | xargs clang-format-3.9 -i -style=Google (#740)

* fix code styles

* Update offline_lidar_visualizer_tool.cc

* publish ins message; delete unused file.

* imu message add euler angles.