fix(avatar): prevent avatar from obscuring name

Increase z-index of avatar-name so that avatar image doesn’t obscure it
when riding a mount
fix(tasks): improve UI consistency and layout

* Match UI elements with rest of site
* Tidy up layout
Closes #4361
Merge branch 'develop' of github.com:HabitRPG/habitrpg into develop
Changing button to a element fixed the delete on enter problem
feat(event): Implement Seasonal Shop
fix(event): Better shop flow
feat(event): Mystery migration
feat(event): Quests and Bailey
fix(event): quest syntax
fix(event): Better quest text placement
Merge pull request #4408 from SabreCat/seasonal

Winter Wonderland 2015 Cont'd