Add POE::Test::Loops to config_requires, so modern systems can install
it before Makefile.PL runs. Allow gen-tests.pl to fail gracefully if
POE::Test::Loops isn\'t installed. Remove a bunch of tabs from
Use POSIX::_exit(0) for the event loop tests when they\'re
run in ActiveState Perl. POE::Wheel::Run (perhaps the forking)
crashes Perl when the wheel_run.t test is run with Tk\'s event
loop. Using POSIX\'s _exit() seems to avoid the problem.
Add the ability to skip certain classes of tests on certain platforms,
then use it to skip the IO::Poll tests on MSWin32. First, IO::Poll is
kinda broken on MSWin32 and falls back to select() anyway. Second,
some of the tests break outright in the IO::Poll fallback tests.