Make application responsive

[rolandgeider]

The django-mobile application is currently not compatible with django 1.10 and seems to be slowly discontinued. While there is a workaround for this specific problem (see gregmuellegger/django-mobile#72), this would be a good opportunity to make our application truly responsive and not depend on browser sniffing or such (even more considering that bootstrap provides many helpers for this).

There are currently two templates for a couple of pages, a regular one and a mobile one. The mobile template is in a subfolder called "mobile", e.g.manager/templates/mobile/workout/view.html vs manager/templates/workout/view.html. These need to be adapted, deciding in a case by case base how to do it (make both the same, hide some navigation elements for certain sizes, etc.). There is also one instance where we check for in python code (set.py), otherwise just search "flavour".

[rolandgeider]

Definitely something to do for 1.9

[rolandgeider]

This involves removing all the ua_aware_renderer, the TEST_MOBILE variable check for thests (and the travis conf) as well

[rolandgeider]

With the merging of feature/mobile-templates, this issue can be closed. Note, that while all hard-coded checks for user agents or similar were removed, the application is not completely optimized yet