Ensure Quantity.round always works; wrap methods with less boilerplate
Adapt places where "wrong" np.round led to the right result
Add changelog entry [skip ci]
Ensure test_std_inplace always fails, as it is broken in numpy
Avoid keyword arguments where possible to resolve numpy 1.5 failures
Update _wrap_function doc string, correct and test nansum out option
Merge pull request #3062 from mhvk/quantity-round

Ensure Quantity.round always works; wrap methods with less boilerplate