A few code style changes

* Replace properties requirements by _.defer
    That's now what we use to build apps.
* Factor requests URLs and use helpers.fmt
* Reuse safeGetPath to simplify condition
* Change how this.customer is created
* Bind callback instead of introducing that
* Remove unnecessary variable
* Remove some vertical space and fix indentation
* Remove unnecessary variable
Use a custom field to fallback if no user is found
Add a setting to hash the email address for search
Add settings labels
Merge pull request #2 from totango/pelletier/improvements

A few style changes + new features