realpath: Fixing undefined behaviour in the second test. If the call fails the resolved_name argument cannot be used for error checking because its state is undefined by SUSv2.
pipe: Changing the order of close and write error handling code. Errors in close could overwrite errno after write errors, returning incorrect error messages.
gmtime: Removed duplicate checks
Other fixes for fseek, rename, mktime, putwchar
This will allow us to redefine the exit function.
For example:
```
#define exit(code) { \
fprintf(stderr, "%s:%d: exit(%s) in function ‘%s’\n",
__FILE__, __LINE__, #code, __func__); \
_exit(code); \
}
```
Apparently gmtime was already implemented when I made localtime, so we had two different things written from scratch. We decided in the relibc channel of the Redox OS Mattermost chat to use my code, as it is more extensively tested and perhaps is clearer in how it works.
Peter Limkilde Svendsen