This new function does the same as newRow(), except that it has a less confusing
name (in line with _add_Column()), and accepts printf-style arguments to avoid
the need to newRow(qPrintable(QString::asprintf())), a common pattern in client
code. It uses qvsnprintf() under the hoods, avoiding the need for the QString
const char* round-trip.
Port all in-tree users of newRow(qPrintable(QString::asnprintf())) to the new
function.
Change-Id: Icd5de9b7ea4f6759d98080ec30f5aecadb8bec39
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>