Version Control With Subversion Source

* en/book/ch09-reference.xml
(svn.ref.svn.sw): Document the other forms the --change
option supports.

* en/book/ch04-branching-and-merging.xml
(svn.branchmerge.basicmerging.mergeinfo): Add a tip explaining
that "mergeinfo" is just shorthand for the svn:mergeinfo
property. We use this shorthand a bit in the book, but more
importantly it is used extensively everywhere else. Also
add "mergeinfo" to the index.

* en/book/ch04-branching-and-merging.xml
(svn.branchmerge.basicmerging.mergeinfo): Describe the new 1.7
notifications which occur when a merge updates mergeinfo to
describe a merge (as opposed to the traditional notifications
which describe the application of a diff).

Translation of "Tunneling over SSH". Closes ticket #314 (cf.
http://www.svnbook.de/ticket/314).

Trivial grammar fix.

"interactively" -> "interactive"

Add release date for Subversion 1.7

"(???)" -> "(October 2011)"

Apply 1.7-style notifications to all 'svn merge' examples.

* en/book/ch04-branching-and-merging.xml
* en/book/ch09-reference.xml

* en/book/ch04-branching-and-merging.xml
(svn.branchemerge.basicmerging.stayinsync): Fix some typos and throw
<command> tags around some subcommands.

* en/book/ch04-branching-and-merging.xml
(svn.branchmerge.advanced.finalword): Tweak a recommended best
practice to reflect 1.7 reality.

* en/book/ch04-branching-and-merging.xml
(svn.branchemerge.basicmerging.stayinsync): Demonstrate the new 1.7
restriction on mixed-rev merges in one of the early merge examples.