Performs a timeval substract leaving the result in (result).
Subtract the `struct timeval' values a and b, storing the result in result.
- Parameters:
-
| a | First parameter to substract |
| b | Second parameter to substract |
| result | Result variable. Do no used a or b to place the result. |
- Returns:
- 1 if the difference is negative, otherwise 0 (operations implemented is a - b).
