Velo/Horizon/Trail/Aventura 4.2.1

New features

• 'Sound alarm' enabled by default in alarms. So no need to enable alarm and then enable sound.
• Improved management of 1:50.000 layer in mosaic topo maps which have both 1:25.000 and 1:50.000 layers (e.g. Great Britain Topo).
• Added 'Emergency' button as option for toolbar (SeeMe) 
• 'North Up' is now the default setting for hiking instead of 'Track Up'. 

Solved bugs 

• Audio volume abnormally low in some Trail/Aventura units 
• Garmin ANT+ sensor not connecting
  Warning: this change will re-start sensors configuration, so all sensors will have to be paired again.
• Other minor bugs solved