[Feature request] Add activity type setting

[gwarnants]

Hello,

It would be very nice to have an "activity type" setting on the main screen, or somewhere else in the settings, to describe which kind of activity we are currently doing (it could be walking, running, cycling, driving, or any activity Gpslogger could be used for). This new information would also be saved in our tracking history and uploaded to the custom url feature using a new parameter, ie %TYPE