Loans created on the checkout page and the product page used different
functions to look up users, causing inconsistent behaviour. Now both use the
"advanced" user lookup that will initialize users that don't currently exist
in the system.
Supported length keywords are day, week, month and year. The plural forms
are also valid. There may be minor differences in the semantics of
the time string between the preset list and the default length setting,
due to the default length being computed by php's Date object,
while the preset list is computed in javascript on the client side.
