3493 & 3962 Tweak edit profile, user name, password, and email pages

https://code.google.com/p/otwarchive/issues/detail?id=3493 https://code.google.com/p/otwarchive/issues/detail?id=3962

Issue 3493: Firefox had a bug where it was impossible to change your user name in some instances. To get around this, we changed the order of the fields on the Change User Name page. But Firefox fixed this, so we no longer need that workaround. This puts the Password field back below the New User Name field while keeping some HTML tweaks that were included in the original pull request.

Issue 3962: So many tabs needed to be converted to spaces. Aside from that, let's just copy from the issue here...
  1. The forms for changing email, user name, and password all require the user to enter their existing password. The field for doing that should be in the same place on all the forms. Let's go with *after* the email, user name, and new password fields, i.e. at the bottom.
  2. The pages for edit profile, change email, change user name, and change password all use the same navigation. Let's put it in a partial so we're not writing the same 12 lines of code in four different places.
  3. The button on the forms for changing email and changing password say "Change Email" and "Change Password" respectively. Let's make the button for chaining user name say "Change User Name" instead of the current "Change" because less generic labels on actions are good.