Version Control With Subversion Source

* src/en/book/ch07.xml
(Subversion Repository URLs): Was 'URL Construction'. Massage the
text to not refer to Chapter 2 (*especially* as plain text instead
of an <xref>). Also fix a spelling oops.

* src/en/book/ch08.xml
(Repository Layer): Tweak to not claim that FSFS is a database.

Tweak chapter 5 txn-cleanup stuff.

* src/en/book/ch05.xml (Repository cleanup):
Don't say that zombie txns 'consume resources'; be less alarmist.
Don't mention that dead-txns can result from failed updates; they can't.

* src/en/TODO: remove item.

Re-org docs on how URLs are parsed.

* src/en/book/ch02.xml (Repository Access URLs): shrink sidebar to
just a table of URL schemes, with a link to new ch07 section.

* src/en/book/ch07.xml (URL Construction): new section; absorb the
text from the ch02 sidebar and also mention URL autoescaping.

* src/en/book/TODO: remove TO-DO.

Tweak beginning of chapter 8 to mention FSFS. Very small change.

* src/en/book/ch08.xml
(Repository Layer): mention BDB and FSFS both.
(A Brief Inventory of the Subversion Libraries):
list libsvn_fs_base and libsvn_fs_fs in table of libraries.

* src/en/book/TODO: remove item.

Document subversion's use of locale.

* src/en/book/ch07.xml: new "Localization" section.

* src/en/book/TODO: remove item.

Book Spanish. Translated two paragraphs.

Book Spanish. Translated two paragraphs.

* src/en/TODO: better explain strategy for URL docs.

Tweake appendix C in the 1.2 book branch.

* src/en/book/appc.xml: left-justify <screen> contents.

* src/en/TODO: tweak to reflect that the Appendix C rewrite is finished.