Add filter to show a level title given a number

In the new interface, given a level we display a message:
2: Easy
4: Easy/Medium
8: Medium
16: Medium/Hard
32: Hard
Fix question list when creating new question set

They are now reinitialized correctly when a new question set is
displayed to the user
Merge pull request #21 from mlopez-firstfactory/master

Level filter, fix question list when a new set is created
Add custom modal.

* this modal will be shown once the user gets into the final question of one set, to ask him :
- if he wants to continue working on the same track.
- or if he want to play in another track.
Improve styles practice page.
Modify Html directives in order to show answered percent even if the answers does not have any explanation.
Fix answers status and  missing method call.
Add hyphens when the user clicks on 'show answer'

Whenever the user clicks in the 'show answer option' we now display
hyphens instead of the actual data and as the wrong or right answer
icon.
Merge remote-tracking branch 'upstream/master'
Remove  unnecessary style.
Add missing function inside question.ctrl.js
Remove overflow-x from answers box.
Merge pull request #22 from mlopez-firstfactory/master

Now showing hyphens when user clicks on 'show answer'
Add reset layout.
Implement Jeff's feedback

Remove the text 'You took more...' and the 'i' circle when displaying a hyphen
Add validation in order to shown question analytics just for gre,sat,act and gmat.
Merge pull request #23 from mlopez-firstfactory/master

Implement Jeff's feedback
Add analytics validation on question view.
Merge pull request #53 from joanrm20/master

Maua client new features and fixes