Added/modified profile-related preferences

Resolves #919.
Resolves #907.
Resolves #1077.

http://jenkins.buttonweavers.com:8080/job/buttonmen-AdmiralJota/190/

* Public email address option
* Gender field
* DOB split into month/day

Dependent on  #1067.
Tiny code tidiness thing, don't worry about it unless you're making other changes: because of the backslash and the relative likelihood that we might want to change the text used in the "Specify" gender case later, i think that text string should be a variable here.