exclude optimised builtin methods from being the Python method call optimisation (previously broke code generation)

disable syntax support for "yield" expressions in function argument annotations and default args which never worked and crashes the compiler

This solves the issue reported by Volker Braun where conflicting
using aliases of uint64_t would result in compile time errors.

Unfortunately, this also means that it's always included if
CYTHON_USE_PYLONG_INTERNALS is set, but it's a short header.

- comma at end of any argument list (even in lambdas)
- "yield from" does not accept implicit tuple arguments

- comma at end of any argument list (even in lambdas)
- "yield from" does not accept implicit tuple arguments

disable syntax support for "yield" expressions in function argument annotations and default args which never worked and crashes the compiler

make C char* string literals "const" unless specified otherwise

Conflicts:
	CHANGES.rst

gcc older than 4.7. This fixes a recurring Travis build failure.