Bring back roadmap_label instead of roadmap_label_fast

[meirtsvi]

I replaced roadmap_label with roadmap_label_fast since it contained many 'free' calls which causes massive amount of lookups in linked_lists (look at smalloc.c for the implementation of malloc and free).

This causes the map not to contain all street names but rather the most important ones which can be annoying.

Executing large amount of 'free' calls can take up to 50% of the device CPU. I would suggest to closely monitor the free calls and see if the implementation can be replaced with pre-allocated buffers instead of malloc-free pairs.