Document that we need to update the ecpg regression files when we update

the library version number.

src/tools/RELEASE_CHANGES

@@ -35,6 +35,7 @@ For Major Releases
 * Bump library versions, if appropriate (see below)
 	o src/interfaces/*/Makefile
 	o src/interfaces/*/*/Makefile
+	o update ecpg regression expected files
 
 * Release notes
 	o check that dashed items from the TODO list are complete