[fix bug 904862] Use IntegerField in SearchForm.

- Use IntegerField in SearchForm.
- Update HTML of Search.
[fix bug 908673] Display username on public pages when display_name is private.
[fix bug 909333] Logout from Persona when visiting logout view.
[fix bug 885504] [fix bug 837787] Really delete and logout user on delete.
[fix bug 910606] Display logo and site name in Persona login.
Merge pull request #597 from glogiotatidis/browserid

[fix bug 910606] Display logo and site name in Persona login.
Merge pull request #584 from glogiotatidis/904826

[fix bug 904862] Use IntegerField in SearchForm.
Merge pull request #590 from glogiotatidis/908673

[fix bug 908673] Display username on public pages when display_name is private.
Merge pull request #593 from glogiotatidis/837787

[fix bug 909333] Logout from Persona when visiting logout view.
Tshirt model field defaults to None.
[fix bug 907665] Timezone dropdown defaults to None.
Merge pull request #586 from glogiotatidis/907665

[fix bug 907665] Timezone dropdown defaults to None.
[Bug 888006] Added tshirt field and privacy control
Merge pull request #598 from fxa90id/Bug_register_page

[Bug 888006] Added tshirt field and privacy control