Implement "Change username" feature
refactor(game-pane.styl): tweak layout and colors

– Improve positioning and size of chat-box buttons
– Replace some px values with ems
– Replace contributor colors with variables (set in global-colors.styl)
fix(global-modules): prevent labels from hiding tooltips

– Remove overflow:hidden from label template as it obscured tooltips
applied to label’s children
– Style buttons correctly if they include an input element
fix(dilatory): dont' modify original user.progress on world boss dmg,
fixes #3737
bailey(dilatory): mobile update, dilatory changes
fix(bailey): add links to recent update
feat(admin): allow admins to update user's items (restoring lost items,
granting quest scrolls, etc). @deilann :)
feat(dilatory): add dilatory achievement
remove beta from api call examples

The API documentation examples used beta.habitrpg.com as url. Additionally, the base URL was specified including "/user/". removed both to avoid confusion and make copy-paste easier
Merge pull request #3754 from vIiRuS/patch-3

remove beta from api call examples
Merge pull request #3597 from 3onyc/feature/username-change

Implement "Change username" feature
Fixed #3756?

It seems to be fixed, but I don't know the good development habits for
jade/whatever technology it is. Please comment & close if the fix is not
acceptable.
Merge pull request #3760 from Skyyrunner/develop

Fixed #3756?