remove 'request' from global registry

When TestRestExport tests run, this causes problems in later tests
that validate anti-spam fields.  Specifically, `make_spinner` returns
a different value the first time, due to the remote_addr being
set to 1.1.1.1
[#6813] Don't send success event if app not created

Signed-off-by: Tim Van Steenburgh <tvansteenburgh@gmail.com>
[#6610] Improve trac ticket content formatting

Signed-off-by: Tim Van Steenburgh <tvansteenburgh@gmail.com>
[#6610] Don't replace shortlink patterns in raw text blocks

- This was necessary when we were fetching raw ticket text during export.
  Now that we're fetching html, things that should be links are already
  <a> tags. Any remaining shortlink-like patterns in the ticket text
  should *not* be converted to links.

Signed-off-by: Tim Van Steenburgh <tvansteenburgh@gmail.com>
[#6610] Move Trac-specific parsing to subclass

Signed-off-by: Tim Van Steenburgh <tvansteenburgh@gmail.com>
[#6692] add license headers to new files