actually flush
raise ruby errors if io is closed
Merge remote-tracking branch 'origin/tim/IO#flush'
first stab at IO.popen
much simpler IO.popen, few features
Revert "much simpler IO.popen, few features"

This reverts commit ddecdc094ae51c2e6cb01bc5542de52d86d28c9b.
fix typos
use IO.pipe, IO#reopen, and Process.fork to implement simple pure-ruby IO.popen
move close, closed? to IO, re-add pipe, as it got lost
fix translation, use Process.exit
try to make reopen work correctly for opened streams
translation fix
add fork test
add IO.pipe tests
add Process.fork and Kernel#fork
add fork test
Merge remote-tracking branch 'origin/master' into tim/IO.popen

Conflicts:
	topaz/objects/fileobject.py
send exit, don't just do it
Merge branch 'tim/Process.fork' into tim/IO.popen
Merge branch 'tim/IO-raise-errors-if-closed' into tim/IO.popen

Conflicts:
	topaz/objects/fileobject.py