adding DoubleField
Add DoubleField Type
Delete Tuple test pass
InsertTupleTest pass
DeleteNonExistTupple Test Pass
testDirty Pass
Heapfile not finished
spelling correction
Agregate test Pass

System and unit
New bufferpool implementation

Using Linked List and LRU
cleanup of HeapFile
Flush and Flush All without test
not working FileWrite Test
FilePageWrite Test Passes
Insert and delete in bufferpool