turn off exceptions by default where they aren't required

turn off exceptions by default where they aren't required

This significantly reduces the size of the generated code
in places where we don't need exceptions.

The -(no-)exceptions configure flag has been removed in the
process, as there is now a fine grained way to control this
on a per module level, and Qt is being compiled without
exceptions in most places.

Change-Id: I99a15c5d03339db1fbffd4987935d0d671cdbc32
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>