refactor scope handling in ScopedExprNode, enable type inference for inlined genexpr nodes, fix type coercion of sum(genexpr)

cy exec test + correct building of locals dict in Cython frames for non-wide python 3 unicode builds

--HG--
rename : tests/run/lambda_module.pyx => tests/run/lambda_module_T603.pyx

setup.py option '--cython-compile-all' to compile more Cython modules during installation than enabled by default

Choose PyString/PyBytesObjectPtr according to python version + support signals terminating the inferior.

--HG--
extra : rebase_source : 7fea7f050894df69b66a2bdb843ce1885ef7ef7a