Fix conversions from pointer to int and vice versa

Fix conversions from pointer to int and vice versa

Here the int values fds[0], sigfd, s, sock and fd are converted
to void pointers which are later converted back to an int value.

These conversions should always use intptr_t instead of unsigned long.

They are needed for environments where sizeof(long) != sizeof(void *).

Signed-off-by: Stefan Weil <weil@mail.berlios.de>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>