Reduce number of times "full track" alert shown

One time is enough for "All available tracks
retrieved" alert to be shown.
Fix buttons positions sticking to each other.

If do "fitAllPilots" when map is hidden,
then custom buttons move to wrong positions on
the map with several buttons piling up on the
same place. So avoid calling that method before
the map is shown.
Merge branch 'master' of https://github.com/new-mikha/flytrace