This effectively removes the temporary hacks introduced in r73486 (a35a785b)
and in r73487 (0ce031f7) for the LocalService and NetworkService accounts.
Now these accounts (and their corresponding user profiles) are created
on the fly, the first time a service that needs these is started.
The code introduced in r73501 (ade0d2cd) is now re-enabled: this has
been made possible thanks to commit f42b4bbe (thanks Eric!).
Dedicated to Joachim Henze ;-)
CORE-12541, CORE-12279