BAPI - mapmanip submap perf improv + mapmanip script

[DreamySkrell]

changes:

• rscadd: "BAPI - mapmanip submap performance improvements."
• rscadd: "BAPI - mapmanip script."

perf improv in the form of changing the map container from hashmap to a flat grid hashmap was only bad for big maps with lots of submaps - did not affect horizon with its one small submap

the script:

[DreamySkrell]

!build_bapi

[DreamySkrell]

!review