- Tidy up that netware mess by performing a configure check which will
define the symbol PHP_CAN_SUPPORT_PROC_OPEN if PHP can support proc_open.
- Protected the proc_open specific code with #ifdef PHP_CAN_SUPPORT_PROC_OPEN
so that user-space scripts can use function_exists and react accordingly.
** Heads Up Win32: You need to add ext/standard/proc_open.c to the DSP and
** #define PHP_CAN_SUPPORT_PROC_OPEN in the w32 config header.
