fast map

[abuts]

According to Re #1825 implemented fast map to use to access indices.

Adds class providing fast map functionality to the code to use in maping between pixels and IX_experiments.

fast_map_vs_map_performacne routine shows, that the class, if oprimized, works 100 times faster than standard MATLAB containers.Map. If not optimized, is still 5 times faster for search and 11 times faster for search and insertion.

Find & Add keys to UINT        map   takes 324.988sec
Find & Add keys FAST MAP       map   takes 27.3212sec
Find       keys in UINT        map   takes 89.579sec
Find    keys in FAST MAP       map   takes 19.6152sec
Find all keys in FAST MAP      map   takes 18.6721sec
Find keys in FAST MAP Opt      map   takes 0.803015sec
Find all keys in FAST MAP opt  map   takes 0.304346sec

[abuts]

Solves #1825