Version Control With Subversion Source

* src/de/book/ch01-fundamental-concepts.xml
- Enhanced translation of the copy-modify-merge
section.

* src/de/book/ch01-fundamental-concepts.xml
- Fixed coding problems.

* src/de/book/ch01-fundamental-concepts.xml
- Enhanced german translation of the section
"The Lock-Modify-Unlock Solution"

Minor wording tweak that I suspect O'Reilly's copyeditors would
have smacked me for writing in the first place.

* src/en/book/ch03-advanced-topics.xml,
* src/en/book/ch04-branching-and-merging.xml
Tweak some wording to avoid implying untrue things only revealed as
untrue if the reader keeps reading long enough to hit the revelation.
. o O ( Huh? )

Suggested by: James Kistruck <James.Kistruck {at} dataconnection.com>

* src/en/book/ch09-reference.xml,
* src/en/book/ch03-advanced-topics.xml,
* src/en/book/appb-svn-for-cvs-users.xml,
* src/en/book/ch05-repository-admin.xml,
* src/en/book/ch06-server-configuration.xml,
* src/en/book/ch04-branching-and-merging.xml
Make a handful of mostly minor wording or formatting fixes found
during our ORA QC1 review cycle.

* src/en/book/ch02-basic-usage.xml
Fix diff description problem -- it can compare repository revisions,
not compare two different repositories with each other.

Suggested by: Jens M. Felderhoff <j.m.f {at} gmx.li>

* src/en/book/ch06-server-configuration.xml
Clarify which username gets credited for a commit in the
svnserve-over-ssh situation.

Patch by: Vincent Lefevre <vincent {at} vinc17.org>
(Tweaked by me.)

* src/en/book/ch02-basic-usage.xml
Rework some stuff to avoid talking about "checking in", which is
explicitly forbidden in our HACKING document. As a side-effect,
lose a reference to making changes to a file "in a repository",
since those changes are in fact made in the working copy and
explicitly *not* transferred to the repository in this particular
example.

More minor typo tweaks from Øyvind A. Holm <sunny@...>, plus a
reworking of a couple of paragraphs for readability and to avoid an
awkward use of an mid-sentence screen output example.

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