Version Control With Subversion Source

Amend the rules for subcommand option descriptions.

* src/en/book/ch08-embedding-svn.xml
Revive a portion of the old Programming With Memory Pools section
from the 1.2 version of the book as a sidebar. (Sorta.)

* src/en/book/ch08-embedding-svn.xml
Commit up changes based on most of Ben's review of Ch 8.

* src/en/book/styles.css
Make <structname> tags look like other fixed-width markup.

* src/en/book/ch05-repository-admin.xml
Finish the last review item from Ben's feedback on chapter 5.

* src/en/book/ch05-repository-admin.xml
More tweaks from Ben's gracious review. (Including the cool row-span
thing in the comparison table he was asking for!)

* src/en/book/styles.css
Stop wasting so much valuable horizontal space on special-block margins.

I've tried four of five different DocBook tweaks to make the reference
chapter into what I'm looking for, all failures. For now, I'll just
rename the thing for consistency with the rest of the book parts.

(And I'll very likely be consulting with O'Reilly's tools team about
what options exist for making this thing work.)

* src/en/book/ch-reference.xml
Renamed to ...

* src/en/book/ch09-reference.xml
... this.

* src/en/book/book.xml
Track the rename.

* src/en/book/ch02-basic-usage.xml,
* src/en/book/ch03-advanced-topics.xml,
* src/en/book/ch04-branching-and-merging.xml,
* src/en/book/ch06-server-configuration.xml:

Try to consistify our use of long and short options, based on
new HACKING rules.

* src/en/book/ch05-repository-admin.xml
Move the guts of dump-filtering into its own new section, leaving only
a stub description of svndumpfilter in the Administrator's Toolkit
section. Also created a new stub in that section for svnsync.