* child_info.h (CURR_CHILD_INFO_MAGIC): Update.

* child_info.h (CURR_CHILD_INFO_MAGIC): Update.
(child_info::parent_wr_proc_pipe): Eliminate.
* pinfo.h (_pinfo::alert_parent): Move here from pinfo class.
(_pinfo::dup_proc_pipe): New method.
(_pinfo::sync_proc_pipe): Ditto.
* exceptions.cc (sig_handle_tty_stop): Reflect move of alert_parent.
* init.cc (dll_entry): Exit with status one if main process called ExitProcess.
* pinfo.cc (set_myself): Remove handling of parent_wr_proc_pipe.
(_pinfo::exit): Reflect move of alert_parent.  Set procinfo to NULL to flag
that we are exiting normally.  Always use exitcode when exiting
(although this could be a little racy).
(pinfo::init): Set default exit to SIGTERM.  This will be the exit code
reported if process is terminated.
(_pinfo::dup_proc_pipe): New function.
(pinfo::wait): Duplicate wr_proc_pipe to the right place.  Use dup_proc_pipe to
move the pipe to the child.
(_pinfo::sync_proc_pipe): New function.
(_pinfo::alert_parent): Move to _pinfo.  Make sure that wr_proc_pipe is ours
before using it.
* sigproc.cc (child_info::child_info): Remove handling of parent_wr_proc_pipe.
* spawn.cc (spawn_guts): Pass our wr_proc_pipe to the child when execing.
Ensure that exit code of cygwin process started from windows is correctly set.