merged in latest cython-devel

diff --cc Cython/Compiler/ExprNodes.py
Simple merge

diff --cc Cython/Compiler/Main.py
Simple merge

diff --cc Cython/Compiler/ModuleNode.py
Simple merge

diff --cc Cython/Compiler/Nodes.py
Simple merge

diff --cc Cython/Compiler/Optimize.py
Simple merge

diff --cc Cython/Compiler/ParseTreeTransforms.py
Simple merge