Workouts data updates with Avg HR.
Using real HR avg.
Added 'Coming soon' for elevation button.
Separating day cells, workouts & month borders into 3 containers.

This is to avoid z-index overlapping when elements are added/removed
(before they would mix up, now they stay in their respective containers).
Page reorganization to make it look OKish on default screen size.
Removing day selection on year change.