Version Control With Subversion Source

Found one spelling mistake in svn_version.h that led to a spelling
mistake bug hunt.

As of revision 5618, repositories and working copies now use
README.txt instead of README, and they use local eol style in those
files. This revision makes the analogous change to
~/.subversion/README, and adjusts the book for all of these changes
(thanks to Mike Pilato for reminding me of the docs):

* subversion/libsvn_subr/config_impl.h
(SVN_CONFIG__USR_README_FILE): Add .txt extension.

* subversion/libsvn_subr/config_file.c
(svn_config_ensure): Use APR_EOL_STR instead of "\n".

* doc/book/book/ch05.xml, doc/book/book/ch06.xml,
doc/book/book/ch08.xml: Use the new filenames.

* ch06.xml: fix copy-n-pasto in sidebar.

Fix issue 1227.

* doc/book/book/ch08.xml
correct typo, 'svn create' should be 'svnadmin create'.

Submitted By: Dmitriy Popkov

* doc/book/book/ch07.xml
(Layered Library Design): libsvn_auth no longer exists, so take it out of
the list of libraries.

* ch05.xml: use mdash instead of semicolon.

* ch05.xml: clarify that SSH means no svnserve daemon is needed.

Some clarifications and minor corrections to the Subversion book.
Patch from Julian Foad <julianfoad@...>.

* doc/book/book/ch03.xml:
Change wording to encourage users to issue "svn resolve" rather than
removing the temporary files manually. Change of emphasis for clarity.
Insert a missing word.

* doc/book/book/ch08.xml:
Explain why "ci" and not "co" is the abbreviation for "commit". Fix
spelling.

* doc/book/book/ch02.xml:
* doc/book/book/ch04.xml:
* doc/book/book/ch05.xml:
* doc/book/book/ch06.xml:
* doc/book/book/ch07.xml:
Grammer/typo/spelling/mdash fixes.

Fix WebDAV RFC number. Noted by Tez Kamihira.

* doc/book/book/ch07.xml: Change "RFC 3256" to "RFC 3253."

* notes/webdav-general-summary: Likewise.

Remove out-of-date comments.

* doc/book/book/appa.xml, doc/book/book/ch04.xml,
doc/book/book/ch06.xml: Remove out-of-date comments.