As it turns out, they're rather annoying to maintain, and we don't even need
them. They also clutter the code unnecessarily in their current form.
If it ever comes to having to have them, let's make another version of
error_set(), maybe error_set_with_code(), that makes it possible to also set
an integer within `struct error'.
The only problem with the above solution is when we aggregate errors from
multiple functions (be it by calling one after another, or through nesting of
functions that may return an error).
But let's care about that when the time comes for it.
As it is going to share a great lot of functionality with ZyklonB, I have
decided to extract the common parts into `common.c' and make the two subprojects
include this file.
The Single Compile Unit concept has proven valuable (sub-second compile times,
dead code warnings, almost no need for function declarations, whole-program
optimizations), and the sources aren't that long so far anyway.
I am probably going to add CMake support later but so far it's not a priority.
This project is meant to be portable and freely relocatable (ie. no hardcoded
paths if I can avoid it).
