Version Control With Subversion Source

Small fix to a bug noticed by Robert Tasarz (robert.tasarz@...).

Book Spanish. Translated 12 paragraphs.

German Book: Change revision number from what it used to be when the book was
part of the Subversion repository, to the actual revision number that it became
when the book moved into its own repository.

* de/book/book.xml: r7314 there is r353 here.

Followup to r1231, which changed some section ids. Repoint an xref which was
now pointing to the wrong place.

* en/book/ch04.xml: Fix <xref>.

* src/en/TODO: start scoping 1.2 doc work.

* src/en/TODO: divvy up the remaining 1.1 doc work among ben/fitz/mike.

* src/en/book/ch04.xml:

- don't use HEAD in merge command examples, it's not really a
good practice to encourage.

* src/en/book/ch06.xml:

- mention pre-commit hooks as an option for controlling per-dir
write access with svnserve.

- Merge the too-short "external path-based authz" section into
this paragraph.

- (Servers and Permissions: A Word of Warning): remove
assumption that all repositories are BDB-based.

* src/en/TODO: remove some TODOs.
also, move a TODO from me to fitz, since it's chapter 3.

* src/en/book/ch04.xml (The Key Concept Behind Merging): new section.
Also, rearrange subsequent section id's accordingly.

* src/en/TODO: remove TODO.

Book Spanish. Updated list of words ignored by aspell.

* en/REVIEW: Issue #1216 was essentially an extension of the REVIEW file, but
having a bunch of unrelated comments in an IssueZilla issue is not very
flexible. Transfer the entire contents of the issue here (and close the
issue.)