[UIFe] Last minute small layout tweaks

John Lea requested some last minute tweaks:

1) Move the user name labels down slightly to vertically align with the session badges
2) Make password entries and login buttons (like for a guest account) the same size (done here by making password entries larger)
3) Add a pixel or two between the text cursor and the password characters
4) Make the border around login buttons white instead of orange (to match password entries)

1, 2, and 3 are in upstream merge https://code.launchpad.net/~mterry/unity-greeter/designfixups/+merge/100868
4 is in light-themes merge https://code.launchpad.net/~mterry/light-themes/greeter-white-border/+merge/100856

I'll apply these to Ubuntu's packaging.

I asked on IRC if these changes were OK, and got this:

<jbicha> mterry: ubuntu-docs doesn't document the greeter so minor tweaks are fine with me
...
<Laney> I would say that you should document the uife in a bug
...
<ScottK> I didn't see any release team member approving the UIFe.
...
* Laney will.

So this UIFe is approved, I just have to make the uploads.