Added code for BTreeIndex::Print function.
Merge branch 'master' of https://github.com/davidmichaelryan/EECS_339_BTree
Altered implementation for print function.
Merge branch 'master' of https://github.com/davidmichaelryan/EECS_339_BTree
Added a TODO document, and created sanityCheck.
Merge branch 'master' of https://github.com/davidmichaelryan/EECS_339_BTree
Merge branch 'master' of https://github.com/davidmichaelryan/EECS_339_BTree