refactor type
Also increase maximum key length in instance key regex

Fixup for 59accdc4252afe00d307a1dc6e3811ce957f910c.
Permanently save "disable all tutorials" setting (fixes #109)

This now uses the `no_help` user attribute for this purpose.

Note that disabling of single tutorials is still only stored in a
session cookie.
Merge pull request #477 from nidico/feature-109-remember-disable-all-tutorials-setting

Permanently save "disable all tutorials" setting (fixes #109)
Merge pull request #483 from xi/feature-refactor-type

refactor type
Add optional user attributes