- primarily fixes a bug in _mlist_insert and _pending_flist_insert
- also updates some tests
- disables node data printing on _bt_insertdat with DEBUG_PRINTNODE macro
- initialize root to page offset beyond first node stripe (not zero). Is this
improper? We initialize the mlist at the first va in the root. Maybe that part
should handle the node stripes instead? Don't know if it actually matters.
- fix insert tests
- fix state->meta_pages initialization
- other minor fixes