Fukász Rómeó Ervin / cloud

we don't have FileField in this form so this won't change much

previous way was kinda ugly

http://django-taggit.readthedocs.org/en/latest/forms.html#commit-false

- change default button to simply represent a time
- add max-width 100% for graphs

- highlight the currently selected option
- switch the images via js

Closes #297

also change 1 month to 30 days instead of 4 weeks