in Purchase module when ordering page is left open and then ordering
window closes. Post->LookupAuthor() has been refactored to
Base->LookupNickname() as it's now also used by the Reader module.
Reader module will now try and save author details in nickname cache
and then also use them when rendering content. SimplePie image
handler now returns default spacer.png so as not to break image tags
on cache miss. parse_hcard() no longer defaults author name to
'someone', so updated Notification module to first fall back to
domain from the provided url, and then to use 'someone'.