Version Control With Subversion Source

Some minor tweaks, by way of follow-up to r4351.

* en/book/ch03-advanced-topics.xml
Add a warning about not supplying a log message on the svnmucc
command line.

* en/book/ch09-reference.xml
Add a missing "-v" argument to an 'svn log' example which obviously
used it.

Suggested by: danielsh

Merge r4352 from ^/trunk/en ("Document SVN_ASP_DOT_NET_HACK").

Merge r4352 from ^/trunk/en ("Document SVN_ASP_DOT_NET_HACK").

Finish issue 1 (!!) ("Document SVN_ASP_DOT_NET_HACK variable").

* en/book/ch01-fundamental-concepts.xml
(svn.basic.in-action.wc): Document SVN_ASP_DOT_NET_HACK.

Finish issue 5 ("Document svnmucc").

* en/book/ch09-reference.xml
(svn.ref.svnmucc.re.examples): Flesh out this section.

* en/book/ch03-advanced-topics.xml
(svn.advanced.working-without-a-wc.svnmucc): Add some missing -m
options to svnmucc command lines.

* en/book/ch03-advanced-topics.xml
(svn.advanced.working-without-a-wc.svnmucc): Take another pass at
this section, working in a better example of why you should use
--revision.

Suggested by: danielsh, Bert, julianf, peterS, etc.
via Freenode IRC #svn-dev

* en/book/styles.css
Italicize blockquote attributions.

* tools/Makefile.base-rules:
Allow fetching of DTDs over the network. This allows those of
us on systems (e.g. Cygwin on Windows) that don't have the DTDs
readily available to build the book.

Suggested by: cmpilato

For issue 5 ("Document svnmucc"), begin fleshing out the reference
material for svnmucc.

* en/book/ch09-reference.xml
(svn.ref.svnmucc): Document svnmucc's Actions and Options in new
subsections of this section. Leave a placeholder section for
Examples, too.