Version Control With Subversion Source

This covers:
Issue 118: ("1.7 change: New 'svn log --diff' option")
Issue 119: ("1.7 change: New 'svn diff --git' option.")

* en/book/ch02-basic-usage.xml
Move the coverage of 'svn log' to after 'svn diff', and then call
out the special 'svn log --diff' functionality as a handy shortcut.

* en/book/ch09-reference.xml
Document the following:
svn diff --internal-diff
svn diff --git
svn diff --show-copies-as-adds
svn log --depth
svn log --diff
svn log --diff-cmd
svn log --extensions
svn log --internal-diff

Finish issue #144 ("1.7 change: HTTPv2").

* en/book/appc-webdav.xml
Mention HTTPv2 as a reality, not a future possibility.

Merge from ^/trunk/en r4046.

* en/book/ch06-server-configuration.xml
Minor wording tweak.

Finish issue #143 ("1.7 change: Multi-target update now includes an
update summary.")

* en/book/ch09-reference.xml
(svn.ref.svn.c.update): Add an example of a multi-target update, and
some verbiage around it.

Merge from trunk r4043, whose log message read like so:

Finish issue #78 ("A fuller explanation of '--depth ARG' in section
'svn Options' would be useful").

* en/book/ch09-reference.xml
Provide quick descriptions of the depth values when describing the
--depth option. Add a pointer to the Sparse Directories section in
the description of --set-depth. Note the inconsistent depths at
which --non-recursive is applied to various subcommands.

Finish issue #78 ("A fuller explanation of '--depth ARG' in section
'svn Options' would be useful").

* en/book/ch09-reference.xml
Provide quick descriptions of the depth values when describing the
--depth option. Add a pointer to the Sparse Directories section in
the description of --set-depth. Note the inconsistent depths at
which --non-recursive is applied to various subcommands.

* en/book/ch03-advanced-topics.xml
Mention libmagic by name in a footnote.

Finish issue #120 ("1.7 change: New 'svn upgrade' subcommand").

* en/book/ch09-reference.xml
(svn.ref.svn.c.upgrade): New section.

Merge from ^/trunk/en r4039, minus the allusion to a libmagic
integration. An updated log message might read like so:

Finish issue #96 ("ch03: svn:keywords failing on UTF-16 files as they
are treated binary").

* en/book/ch03-advanced-topics.xml
(svn.advanced.props.auto): Mention the UTF-16 complication.
(svn.advanced.props.special.mime-type): Remove some text redundant
with, and now include a pointer to, the Automatic Property Setting
section.
(svn.advanced.props.special.keywords): Mention that keyword
substitution only happens on non-binary files.