why was libpq.so's version number bumped?

Hi!

subject says it all, I guess. There is hardly no difference between 7.3 
libpq and 7.3.1 libpq. Why the version shift? Isn't the only thing 
rectifying a version shift that there is a change in the API. Maybe there 
is a change, but I cannot find it.

One of the reasons I ask is, if it is a good reason, like say "security", 
maybe I can persuade the FreeBSD port responsible guys to bring the port 
into the upcoming FreeBSD 5.0 release. The port freeze was introduced just 
before pg-7.3 was released, so nothing new will be admitted unless it is a 
security fix, more or less, which means FreeBSD 5.0 will probably ship with 
7.2.3, which would be a disappointment...

Cheers,
Palle