Fix Track list accuracy operation.
Bring back normal way to redirect to practice page.
Add new score prediction message  if all the tracks score predictions related aren't calculated.
Bring back accordion track list.
*Remove groupId parameter from practice game creation.
Remove some depreciated functions and services along the app, since they're no needed anymore.
Remove old un used variables from practice controller.

*It's no needed anymore since the url property from dashboard give us already the url to request. And this includes the group.
Remove un used variables from question controller.
Bring back dashboard integration to redirect to grockit 1.0 for non 'GRE' groups.
Add new 'htmlSanitizer' services..
Implement 'htmlSanitizer'  along the answers body.
Update sanitiser tags.
Validate html for explanation..
validate html as trust.
Merge pull request #116 from joanrm20/master

Maua client validations and improvements