Revert "create a new Topic if the discourse_topic_id doesn't exist"

This reverts commit 253d60fcd258485e5bc65eafc80be1c0f2b805b7.
load h3d js and styles files without ill-effects on discourse
fix username typo in user deleted
ref top-level classes in discourse_* belongs_to
fix topic titles being off-center
improve import scripts
relax username restrictions
fix typo, uploads not upload