add a assignment operator to Array.h

operator=(Array x) copies the data into the this->_data.  It will resize
the data if it is the sole owner, otherwise throw an exception.
turn off debug printing in array.h
Array operator= now will only resize if _data==NULL
Merge pull request #11 from js850/array_problem

define assignment operator in Array
Revert "Merge pull request #11 from js850/array_problem"

This reverts commit a0734bd6e93344ab30cc4bb61dbe0f66262c1e70, reversing
changes made to b3b09c9d0fd5449b1598f9d198dde6f6b81324fa.