Version Control With Subversion Source

* src/en/HACKING
Tweak formatting a bit, and update the sample chapter a bit.

* src/en/book/ch08-embedding-svn.xml
Update all uses of options in chapter 8 to match our new guidelines.
(It's a joke. Can't you take a joke?)

* src/en/book/ch05-repository-admin.xml
Fixup option usage in this chapter. While here, touch up the
svnsync-related to point out the it offers many of the same
authentication-related options that svn does, and that the 1.4 version
has the single-auth-creds bug (that I've since fixed in 1.5.0-dev).

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.