Version Control With Subversion Source

* book/ch07-customizing-svn.xml
Document the http-proxy-exceptions runtime configuration option.
Oversighted noted by Neil Mayhew <neil_mayhew@...>.

Add skeletal svnsync reference matter.

Fork the homepage into a page devoted to older versions.

Minor fixes suggested by cmpilato.

Fixes suggested by cmike.

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

* src/tools/Makefile.base-rules
Make all the HTML-based rules depend on 'valid'.

Fix build errors (note to self: run 'make valid' before committing).

* src/en/book/ch09-reference.xml: Move sidebar inside of sect1 and fix typo.

* src/en/book/ch06-server-configuration.xml: Wrap floating text in
<para> and move warning inside of refsect1.

Remove all spurious uses of 'switch' where we meant 'option' (as in
cmdline options). This fixes issue #73.

* src/en/HACKING: Clarify our stance on option vs switch for --these
--things.

* src/en/book/ch00-preface.xml, src/en/book/ch09-reference.xml,
src/en/book/ch05-repository-admin.xml,
src/en/book/appb-svn-for-cvs-users.xml,
src/en/book/ch04-branching-and-merging.xml,
src/en/book/ch02-basic-usage.xml: s/switch/option/ where
appropriate.

Fix Issue #65. Eric's review was *awesome*.

* src/en/book/ch09-reference.xml: Incorporate the mega-review changes
from Eric Hanchrow (offby1) into th book

Trac issue 68: small patch from offby1.

* src/en/book/ch06-server-configuration.xml:
(svn.serverconfig.svnserve): note that the "binpath" argument to
"sc.exe" is confusing