trackPopupMenuEx, trackPopupMenu #21

I get unsafe reentries when trying to use either trackPopupMenuEx or trackPopupMenu. They are fixed when I use a safe imports instead.
Also the Microsoft documentation calls the return value of the API functions a BOOL, but the value is actually needed for identifying which option was clicked when the TPM_RETURNCMD flag is set.
I think the return value should be IO (Maybe MenuID). If they get back a zero they should fail like now, if they get back a positive value but the flag wasn't set they should return Nothing and if the flag was set they should return Just MenuID.

Should I send a pull request?