Added distance visualisation.
Minor changes.
Merge remote-tracking branch 'origin/dev' into enhancement/data_center_distances
Added total distribution of distances by sport.
Added personal distribution of elevation gains.
Added total distribution of elevatoin gains by sport and fixed a little
bug.
Tidying it up a bit.
Merge branch 'dev' of github.com:ASE-2014/spoodle into enhancement/data_center_distances
Merge branch 'enhancement/data_center_distances' into dev