Formerly bad code involving unassigned reference temporaries was generated.

Now that we split CInitCode and CppInitCode, we no longer generate
valid C code even if C++ features are not used.

Were these ever used, this would have been an error.

This not only fixes bugs like auto-conversion of std::map[enum, enum] but also
fixes a bug where the compiler-chosen type of int for the enum may not have been
long.

This is a bit of a hack, but as Cython doesn't yet understand
const overloads with different (usually const) return types,
it can't provide the right type of reference in this case.

Many C API calls, both from CPython and externally, expect
PyTypeObject* for the type argument.  A misdeclaration is
a warning in C, but an error in C++.

The C type of other builtins, such as lists, are not typically
required in function signatures, so they are left as PyObject*.

Fixed some memory leaks in Utility/Embed.c

Fixed __Pyx_sst_abs with C++11

Found by clang's static analyzer.
None of those are significant, but we might as well fix them.

Some compilers appear to require you to explicitly `#include <cstdlib>` before
providing `std::abs`.

deep-copy finally clauses of try-finally statements earlier to properly support arbitrary statements in them (genexprs, lambdas, etc.)