#12 Handle leaks

[Paul Sokolovsky]

It seems that pw32 applications are leaking OS handles massively: at the end of runing Perl's Configure, sh running it has ~2000 open handles.

[Paul Sokolovsky]

Investigation shows that two handles are leaked on each fork(): one for synchronization event and one for child's main thread. Event's case is fixed now, but with thread's all is more complicated: simple closing it leads to weird problems.