make control c tests pass on windows. Fixes: #23
don't use CREATE_NEW_PROCESS_GROUP on non-windows platforms.
move platform checks further up test programs
remote spurious tabs
add comment about CREATE_NEW_PROCESS_GROUP
Merge remote-tracking branch 'upstream/master' into ctrlcwin
Merge pull request #24 from kouk/ctrlcwin

Make control c tests pass on Windows.

Fixes #23