update category stream to use new mysql-querier
update category import to work with new mysql-querier
add test for category stream
update boardstream to work with new mysql-querier
update boardstream test to work with new implementation
end mysql-querier in index
handle eror on import-categories
update import-boards to work with new mysql-querier
update userstream to use new mysql-querier
update test userstream
update import-users to work with new implementation
update threadstream to use new mysql-querier
update test threadstream to work with new impelementation
update thread stream to use an inner stream

users will now need to pass in two separate queriers
before this change, the thread stream would fail because
the connection can't handle two large simultaneous queries
update thread test to work with inner stream
update import-threads to work with new implementation

handles two queriers along with new mysql-querier
implementation
update post stream to use new mysql-querier
update poststream test to work with new implementation
update importposts to work with new implementation