DistributedPositioning

TODO improve difficulty:

• generalize to 3d
• increase time between each communication
• non-zero-mean noise

TODO improve accuracy estimate:

• use number of knownNodes and their accuracy to estimate own accuracy
• if knownNodes <= 2 then cost should be 0 and can't be used for estimating accuracy
• stddev(posEst) could be a good estimate of accuracy if it is close to correct position
• switch from scalar 'accuracy' to covariance matrix for each direction

TODO misc:

• find why system does not converge in beginning
• improve search algortihm in findNode