guess longness suffix of negative decimal integer literals based on their type to prevent the C compiler from truncating their value range

Though this path is never taken for unsigned ints, MSVC still throws
warning C4146.

explicitly handle CloneNode in replacement transforms to make sure we take care of its content argument

Conflicts:
	tests/run/iterdict.pyx

Fixes http://trac.cython.org/ticket/864.

--HG--
extra : amend_source : d2a97da4f942d555723b9bfa488985c5e5c27721

explicitly cast digits during PyLong conversion to avoid relying on potentially unsafe C coercion (fixes ticket #865)

revert integer literal suffixing again and instead generate C hex literals if no suffix is used to make the C compiler consider unsigned types for their values (see C standard 6.4.4)

- append U-suffix only on coercion when the target type is unsigned
- append L/LL-suffix when value looks too large for a smaller constant value type

fix bytes literal creation from compile-time DEF expressions (used to become Unicode strings due to missing encoding)