[treesdb] use treedb
[treesdb] get rid of categories in smf-import
[treesdb] use treedb in user import
[treesdb] add type field for treedb in user stream
[treesdb] use treedb in board import
[treesdb] add type field for treedb in board stream
[treesdb] use treedb for thread import
[treesdb] add type field for treedb in thread stream
[treesdb] use treedb for post import
[treesdb] add type field for treedb in post stream
[treesdb] thread stream no longer depends on anything

* does not depend on parent board

* does not use first message
[treesdb] post stream no longer depends on threads
[treesdb] update stat logger to use new labeler methods
[treesdb] use a single statlogger instance
[treesdb] use statlogger end method in index
[treesdb] use a single instance of logfile
[treesdb] board import no longer uses a handler

* handles its own error logging

* handles its own stat logging

* does not need to spawn thread imports
[treesdb] user import no longer uses a handler

* handles its own error logging

* handles its own stat logging
[treesdb] thread import no longer uses a handler

* does not need to handle parent board

* handles its own error logging

* handles its own stat logging

* does not need to spawn post imports
[treesdb] post import no longer uses a handler

* does not need to handle parent thread

* handles its own error logging

* handles its own stat logging