Bug Fixes/Clean up on BTLeafNode

insert(): change m_keys check to Leaf_numberof_entries from Leaf_max_size

locate(): add eid=-1 before returning error code (for easier debugging mostly)

insertAndSplit(): on inserting into a full node, key will now go into sibling or original based on key.
insertAndSplit(): remove check on insert(), use getKeyCount() instead
insertAndSplit(): fix updating keyCounts
insertAndSplit(): change ERROR CODE if sibling node isnt empty

setNextNodePtr(): add extra check for pidsize