ALLJOYN-2135 No longer report multiple copy constructors for ManagedObj

Building Anything with the /W3 flag in Visual C++ the warning C4521: multiple
copy constructors specified will be produced every time ManagedObj is used.

This error is due to the fact that ManagedObj does indeed have multiple copy
constructors.  The code specifically has a non-const copy constructor added to
avoid ambiguity with ManagedObj<T>(A1& arg) constructor. In normal code a const
copy constructor would be all that is needed.

Since the second copy constructor is required for ManagedObj to work.  A pragma
has been added that will tell the windows compiler to ignore this warning for
ManagedObj.  The warning is only ignored for ManagedObj it will still be
generated for other code.

Change-Id: I9a635e530a851841905c4a70310dba8fd1fa376a