Version Control With Subversion Source

* en/book/images/cc-by.png
New image (intended for inclusion with r4200, but ... oops.)

Merge from ^/trunk/en r4328 (dropping mentions of the old -deps
tarball).

* en/book/appa-quickstart.xml
Drop stuff about the -deps tarball. It isn't offered any more, and
INSTALL is the canonical source of installation information anyway.

Finish issue 170 ("In Subversion 1.8, libsvn_ra_neon has been
removed."), save for a small bit regarding library dependencies that
I'll pick up in a subsequent revision.

* en/book/appc-webdav.xml,
* en/book/ch07-customizing-svn.xml
* en/book/ch08-embedding-svn.xml
Make neon go (mostly) away. *Poof!*

Finish issue 181 ("ch09: Document new-to-1.8 SVNUseUTF8 mod_dav_svn
directive").

* en/book/ch09-reference.xml
(svn.ref.mod_dav_svn.conf.directives): Document the new SVNUseUTF8
directive.

Patch by: Neels J Hofmeyr <neels{__AT__}elego.de>
(Tweaked by me.)

Merge from ^/trunk/en r4320 (Copyright year bump.)

Merge r4316 from trunk (^/../ externals definition syntax).

Edited wiki page SvnBook16Status through web user interface.

Edited wiki page SvnBook17Status through web user interface.

Edited wiki page SvnBook18Status through web user interface.