Version Control With Subversion Source

* 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.)

* en/README: Many edits, including some suggested by Jonathon Mah.

Russian Book: Delete the directory. It contained nothing of value.
The readme.txt spoke of changes to the DocBook XSL to output UTF-8, but now
we have shifted from html to xhtml, UTF-8 is the default anyway.
The book XML files were just a plain untouched copy of the English book - but
manually copied and "svn add"-ed, not actually "svn copy"-ed!
There has been no contact with the translators for some time, and if they come
back, we should set up a new ru/ directory that is properly copied.

* ru/: Delete.

German Book: Make it pass XML validation.

* de/Makefile: New - trivially includes Makefile.base.

* de/book/foreword.xml:
* de/book/ch00.xml:
* de/book/ch01.xml:
* de/book/ch02.xml:
* de/book/ch07.xml:
* de/book/ch08.xml:
* de/book/ch09.xml:
Add an XML declaration stating the encoding, and fix numerous small markup
bugs.

* de/book/book.xml:
Merge renaming of © entity to &license; (to avoid clash with standard
HTML entity. Comment out entities for files which do not exist because they
have not been translated. Add a dummy chapter to declare IDs for things
pointed to by IDREFs, but which do not exist in the translation yet.

Spanish Book: Fix invalid XML and migrate to new Makefile system.

* es/book/book.xml: Fix invalid XML (incorrect path to DTD).
* es/book/ch05.xml: Fix invalid XML (spurious duplicate '.' outside </para>)/
* es/Makefile: Migrate to new system.

Norwegian Book: Fix invalid XML and migrate to new Makefile system.

* nb/book/ch05.xml: Fix invalid XML (misplaced </para>).
* nb/Makefile: Migrate to new system.

Migrate the bulk of the locale-independent Makefile out of the locale-specific
"en" directory, and into "tools".

* tools/Makefile.base: Move en/Makefile here, add comment.
(L10N_REVISION): New make variable, to localize word generated by Makefile.

* en/Makefile: Replace with a simple include of Makefile.base.