File handles are signaled when an I/O operation completes, and reset
when another operation is queued.

Get rid of a few WaitForMultipleObjectsEx hacks.

Do not attempt to draw a page during WM_PAINT if there is no active page.

And clean up when disconnecting input.

Also removes dead code caused by the change.

The handle will be closed by free_custom_action_data, so duplicate the 
handle before calling it.

shell32/tests: On Windows 98 FindExecutable() does not '\0' terminate the returned command which caused many tests to fail.

shell32/tests: End the lines with CR+LF otherwise the profile APIs are unable to read them back on Win >= 2000.

Add comments indicating which Windows version returns a given error code.