Add calibration routine for aps array

See merge request !9

# Conflicts:
#   main/commands.c
#   main/commands.h

Scan command

See merge request !8

# Conflicts:
#   main/ftm.c
#   main/ftm_main.c

Add compute distance function

See merge request !6

Triangulation

See merge request !7

# Conflicts:
#   main/commands.h
#   main/ftm.c
#   main/ftm.h
#   main/ftm_main.c
#   main/math_3d.c
#   main/math_3d.h

Cleanup

See merge request !5

# Conflicts:
#	main/ftm_main.c

Refactor

See merge request !4