Fix default settings when they are boolean.
error is that ```enabled ||= true``` always evaluates to true.
Change all initialization of bool settings to use the same syntax:
```setting = true if setting.nil?```
Merge pull request #2653 from jouve/fix_default_settings

Fix default settings when they are boolean.
Add optional signup.
Merge pull request #2050 from dosire/allow_self_signup

Add optional signup