ICCCM compliance: do not use CurrentTime

[hackerb9]

SetSelectionOwner() is supposed to be given a time value that will be reused later. For that reason, we should not be using "CurrentTime". To do so, however, ICCCM suggests do a zero-length append to a property and then check the time on the event we receive. We can do that, but it seems rather a silly way to ask the X Server what the time is. Is there a simpler way to do it that doesn't rely on any X libraries we aren't already using?