Hi,
While following along with Tristan and Heikki's thread about signals
in psql, it occurred to me that the documentation atop pqsignal() is
not very good:
* we don't explain what problem it originally solved
* we don't explain why it's still needed today
* we don't explain what else it does for us today
* we describe the backend implementation for Windows incorrectly (mea culpa)
* we vaguely mention one issue with Windows frontend code, but I
think the point made is misleading, and we don't convey the scale of
the differences
Here is my attempt to improve it.
