Fix the 'how stable is this' paragraph

RELNOTES

@@ -25,11 +25,17 @@ features that are new since version 2.0:
      - Many bug fixes, performance enhancements, and minor new DHCP
        protocol features. 
 
-This release is running in production at the ISC and at quite a few
+This beta release is quite new, and is running in production at only a
-other sites.  At this point, the 3.0 release is reasonably stable, but
+few sites.   We strongly recommend that you exercise caution in
-is really only recommended for sites that are in a position to
+installing it.   The 3.0 Beta 2 lease file is not backwards compatible
-experiment, or for sites that need the new features.  Bug reports are
+with the 3.0 Beta 1 lease file, so if you have to go back, you will
-enthusiastically solicited.
+have to convert your lease files back to the 3.0 Beta 1 format - if
+you try to run a 3.0 Beta 1 server on a 3.0 Beta 2 lease file, it will
+cheerfully delete all your leases.   Having said that, of course the
+way that new releases of open source software become stable is by
+people using them, finding the bugs, and reporting the bugs.   So
+while we urge you to exercise caution, we would also appreciate any
+testing or production use you can safely do.
 
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 as well as how to find documentation and report bugs, please consult