In particular, __LITTLE_ENDIAN__ was not a functioning macro.
Instead, I implemented a version by hand (copied from IBM) that
actually figures out if the machine is little endian or not.
Thank you unit testing!
Instead of using endian.h that is not portable AND doesn't work with
C++, I'll just write my own using a forced union based type punning
trick.
I've decided to use little endian for the format as well: it seems to
be used by most desktop computers so it should make these functions
faster to run for most CPUs.
Have to define _DEFAULT_SOURCE before you can use the endian
conversion functions. As most standard library headers use
features.h, and _DEFAULT_SOURCE must be defined before features.h is
included, we have to include base.h before other headers.
