Initial check-in

This code implements a Grace hash join to simulate the following query :
 select count(*), sum(L_EXTENDEDPRICE) from ORDERS, LINEITEM  where
L_ORDERKEY = O_ORDERKEY
 and O_ORDERDATE between 1995-01-02 and 1996-01-02;

The code uses flat files from TPCH.
Merge branch 'master' of https://github.com/ttmahdy/SpillingHash

Conflicts:
	README.md