Constants in float.pxd are not integers.

Additions to includes

- 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

- 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

undef unwanted defines from longintrepr.h

wrap POSIX dynamic linking API and stdio.h extensions

Fix typo and add missing comma.

Conflicts:
	Cython/Compiler/Optimize.py
	Cython/Compiler/StringEncoding.py

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

This avoids the issue with overloaded address-of operators.