Fix import path and set same requirements as in requirements.txt
Fix the unicode representation for workout objects

This is needed e.g. in the schedule area, where one selects a workout
from a drop down list.
Add date pickers for the start dates of workout schedules
Add a carousel with screenshots to features page

--HG--
extra : amend_source : 1ee046c3d823f472c537621e4eeda4169181ac3c