execvp() in the child branch of a vfork(). Changed to use fork()
instead.
Some of these (mv, find, apply, xargs) might benefit greatly from
being rewritten to use vfork() properly.
PR: Loosely related to bin/8252
Approved by: jkh and bde
This fix only removes the dependency on compile time constants. The code
has other (old) problems that need to be addressed.
PR: 1791
Reviewed-by: bde, tegge