Version Control With Subversion Source

Some more book changes.

* doc/book/book/ch07.xml
Note that the Application Data directory is usually hidden.

* doc/book/book/ch06.xml
Document $SVN_SSH.

Fix the </screen> tag so that "screen" sections don't end in
whitespaceful lines.

* doc/book/HACKING
Adjust description of the proper use of the </screen> tag.

* doc/book/book/appa.xml
* doc/book/book/appb.xml
* doc/book/book/ch03.xml
* doc/book/book/ch09.xml
Adhere to the updated HACKING guidelines with respect to the </screen> tag.

Knock out a bunch of REVIEW tasks.

* doc/book/REVIEW
* doc/book/book/appa.xml
* doc/book/book/ch03.xml
* doc/book/book/ch05.xml
* doc/book/book/ch07.xml
* doc/book/book/ch08.xml
* doc/book/book/ch09.xml

Fix non-uses of <quote>, fix spaces around &mash;, and a bunch of
other little technical stuffs like that.

* doc/book/book/appa.xml
* doc/book/book/appe.xml
* doc/book/book/foreword.xml
* doc/book/book/ch00.xml
* doc/book/book/ch01.xml
* doc/book/book/ch02.xml
* doc/book/book/ch03.xml
* doc/book/book/ch04.xml
* doc/book/book/ch05.xml
* doc/book/book/ch06.xml
* doc/book/book/ch07.xml
* doc/book/book/ch08.xml
* doc/book/book/ch09.xml

Zap stray spaces before and after —

* doc/book/book/ch00.xml: Update markup.
* doc/book/book/ch04.xml: Update markup.
* doc/book/REVIEW: Update note.

Update TODO and REVIEW as I knock items out.

* doc/book/TODO: Update.

* doc/book/REVIEW: Update.

Update diff examples to the 'new' internal diff code output. Since
the diff of this change is a diff of diff output, be careful looking
at the actual diff as it may cause your eyes to melt.

* doc/book/book/ch03.xml: Update diff examples.

Fix markup so that the foreword validates. Also, the gui* tags come
out totally munged in the PDF output, so turn those into something
more... conventional.

* doc/book/book/foreword.xml: Markup/validation fixes.

Bring svnlook into 2004.

* doc/book/book/ch09.xml: Finish updating svnlook documentation.

Some book tweaks:

* doc/book/book/ch05.xml: Fix typo.

* doc/book/book/ch06.xml: Remove stuttered comma.

* doc/book/book/ch08.xml:
- Add missing word "to".
- Use the word "custom" instead of "proprietary" to describe the
ra_svn protocol, and modernize the description of Subversion's
use of WebDAV, both after consultation with Mike.
- In the "Effective Pool Usage" example, actually clear the pool
at the top of the loop, like the comment says, and destroy the
subpool immediately after the loop, which is what most of our
code does.
- Add slashes to the ends of some URLs.