Tags: donglianghere/ikd-Tree

- We upgraded our ikd-Tree to achieve a more stable and efficient per…

…formance. More details are shown as follows:

  - Replace the queue and priority queue in STL with our code to avoid memory conflicts.
  - Fix some bugs in re-building of the previous version, which may result in information loss during the multi-thread re-building process.
  - Add a new parameter max_dist to support ranged search to achieve faster nearest search in robotic applications.
  - Fix minor bugs to improve the overall performance.

Merge branch 'kdtree_loam_test' of github.com:XW-HKU/FAST_LIO into kd…

…tree_loam_test

IMU Propapation as initial values