Bump version to 5.2.1

Update the content and ascii art.

Approved by:    simon(mentor)
PR:             docs/63665
Submitted by:   Jesus R.Camou <jcamou@cox.net>

en_US.ISO8859-1/books/faq/book.sgml

@@ -419,7 +419,7 @@
             only well-tested bug fixes and other small incremental
             enhancements.  FreeBSD-CURRENT, on the other hand, has
             been one unbroken line since 2.0 was released, leading
-            towards 5.2-RELEASE (and beyond).  At 5.3-RELEASE, the
+            towards 5.2.1-RELEASE (and beyond).  At 5.3-RELEASE, the
             5-STABLE branch is expected to be created, and
             &os.current; will become 6-CURRENT.  If a little ASCII art
             would help, this is how it looks:</para>
@@ -459,6 +459,8 @@
                5.2-RELEASE (Jan 2004)
                   |
                   |
+               5.2.1-RELEASE (Feb 2004)
+                  |
                  \|/
                   +
           [5-CURRENT continues]</programlisting>