Child process control in vte and zvt widgets

["nshmyrev" <nshmyrev yandex ru>]

There is problem in application which wants to use terminal widget such as
anjuta and others. One wants to spawn process in terminal and control it's
executuion.

In vte it is impossible to setup child process after fork and befor exec --
like this

vte_fork_pty()
if (pid=0)
  {
  ptrace(PTRACE_TRACEME, 0,0,0);
  exec();
  }
 
In zvt it is possible because zvt_term_fork_pty does only fork, not
exec, and than user can manually do what he wants.  That's why for
example, anjuta use zvt library instead of vte. Zvt, of course, has own
disadvantages, like automatic setup of the child reaper  (This is great
moment in design of vte, thanks a lot! :). And zvt is replaced by vte in
standart gnome libs.

So, is it possible to add a hook to vte, to let user set up child process, like in
g_spawn_async (...., child_setup(), gpointer data,..)
which is called in child before exec()?
I think that will be very useful. 

Thanks.