Version Control With Subversion Source

* en/book/ch06-server-configuration.xml
Document mod_dav_svn's 1.8 keyword expansion feature.

Patch by: Pavel Lyalyakin <pavel.lyalyakin{__AT__}visualsvn.com>
(Tweaked by me.)

* en/book/ref-svn.xml
Fix a weird rendering issue that causes option descriptions to break
across lines.

Patch by: Pavel Lyalyakin <pavel.lyalyakin{__AT__}visualsvn.com>
(Tweaked by me.)

Removed article.

[de] Synced with updated English version.

[de] Added --search and --search-and option description.

[de] Changed "übergeben" to "übertragen" to concur with Subversions
German locale output.

Fix issue 228: Dubious "svn merge" output. Reported by gan.ainm.riomhphost.

* en/book/ch04-branching-and-merging.xml
Fix the output of a 2-URL 'svn merge'.

Reword the description of 'svnadmin lock'.

Made a note that `svndumpfilter` in SVN 1.8 can operate with deltified
dumps (`--deltas`) in `svnadmin dump` command-line reference.

* http://subversion.apache.org/docs/release-notes/1.8.html#svndumpfilter-deltas

Patch by: pavel.lyalyakin{_AT_}visualsvn.com
(Tweaked by me.)

Add `svnadmin lock` and `svnadmin unlock` commands introduced in
Subversion 1.8 to `svnadmin` reference.

* http://subversion.apache.org/docs/release-notes/1.8.html#svnadmin-lock
* `svnadmin lock`: http://subversion.tigris.org/issues/show_bug.cgi?id=3942
* `svnadmin unlock`: http://subversion.tigris.org/issues/show_bug.cgi?id=4092

Patch by: pavel.lyalyakin{_AT_}visualsvn.com
(Tweaked by me.)