most of the bugs worked out for the initial pass at new compaction stratrgy

adding debugging

started work on b+ tree

QIP - further improvements/fixes in BxTree

implemented moving the child nodes on aninner node when it's children split. also fixed a bug
when finding the correct index for insert in an inner node when it's children split.

added a custom compaction Iterable and tried to get it to work.

first pass at impl'ing the BxTreeScanner