avoid runtime 'in' tests for dict literals when we can determine at compile time that there are no duplicate keys

Fix two small sphinx errors in the tutorials

Conflicts:
	Cython/Utility/CythonFunction.c
	Cython/Utility/Generator.c

PyTypeObject members tp_compare, tp_richcompare, tp_base

Conflicts:
	tests/run/generators.pyx

prevent generator methods from returning NULL without setting an exception: method call protocol differs from __next__() protocol

remove test that doesn't apply to normal Python (only to the corresponding .pyx test where it remains)

Conflicts:
	Cython/Compiler/ExprNodes.py

mofe GIVEREF() before PyTuple_SET_ITEM() call because that's when we still own the reference (pypy needs it that way)