Version Control With Subversion Source

Change book's chapter 4 diagrams to match rewritten chapter.

* book/images/branches.ppt: changed source file chapter 4 diagrams.

* book/images/ch04dia2.png, ch04dia3.png, ch04dia4.png: changed diagrams.

* subversion/mod_authz_svn/INSTALL:
Spelling fix.

* doc/book/book/ch09.xml:
Remove a stutter.

* book/ch04.xml: add sidebar about changesets.

Expand my svn:externals TODO.

* doc/book/TODO: more book todo's.

Add TODO item regarding externals.

Eric Wadsworth <wadswore@...> notes that folks should mail the users
list, not the dev list, with BDB troubles.

* doc/book/book/ch05.xml
s/dev@/users@/

* doc/book/book/appd.xml: Stop listing all clients here, just refer to
links page. With Ben Collins-Sussman.

Add a few book review comments.

* doc/book/REVIEW: Add some comments.

Add the missing "$@" to the svn wrapper script in the book.

* doc/book/book/ch06.xml
(Using Multiple Servers): Add the missing "$@".