Found with Clang's `scan-build` tool.
load_file() allocates memory to a char** parameter. It then tries to fread() a
file, and if that fails, frees the memory and returns to caller. However, the
char** is not reset to NULL, which causes a double-free error when the caller
later passes it to free().
Enable a dummy error function to make use of error_strerror() in
third party libraries easier.
Disable if you run into name conflicts and want to really remove the
error_strerror()
