Version Control With Subversion Source

accordingly.

Based on a patch by Chris Pepper <pepper@...>, but modified.

* HACKING:
s/Subversion: The Definitive Guide/Version Control with Subversion/
Update the description of the book, and give its direct web address instead
of how to find it on Subversion's web site (which has changed slightly).

* doc/book/README:
s/Subversion: The Definitive Guide/Version Control with Subversion/, etc.