Tests failures for passing invalid inputs to char-accepting functions

Static property getter and setters expect the type object as the their only argument

One module uses a generic vector caster from `<pybind11/stl.h>` while the other exports `std::vector<int>` via `py:bind_vector` and `py::module_lo

Passing nullptr or None to an STL container pointer is not expected to work

#283: __str__ called on uninitialized instance when constructor arguments invalid

Tests support for C++17 string_view arguments and return values

std::pair <-> tuple & std::tuple <-> tuple

Tests unicode conversion and error reporting.

std::valarray <-> list

#171: Can't return reference wrappers (or STL structures containing them)

std::vector <-> list