Title: Reduced I/O on logins with access time recording or failed login counts
Level: 1
Component: multisite
Version: 1.2.3i7
Date: 1384158368
Class: fix

This change reduces the disk I/O produced by users accessing the multisite
when the user access time recording is enabled. It should reduce I/O in installations
with a large userbase.

In previous versions, these optional features were loading the whole user
configuration just to read / change one attribute of one user, which is kept
in a single file. This mechanism has been recoded to only use this single
custom attribute file.
