**Review .h include needs**

Do not rely on other code to include the files for a given .c, .h file.

`set.h` needs `<stdio.h>` for `FILE`.  
`set.h` needs TBD for `Pair`.  
`get.h` needs `<time.h>` for `time_t`.  
`get.h` does not need `<stdlib>`.  
`set.c` should include "set.h", first.  


**Simplify/imporve `compareString()`**

```
int compareString(const char* a, const char* b) {
  int cmp = strncmp(a,b, 2);
  if (cmp < 0) return 1;
  if (cmp > 0) return 2;
  return 0;
}
```

Perhaps re-write calling code to use `strncmp() result directly?