Version Control With Subversion Source

Sync the Norwegian and English book, r2056:2073.

* src/nb/LAST_UPDATED
Updated by make sync.

* src/nb/book/ch07.xml
Merged r2066, r2070, r2072.

* src/nb/TRANSLATION-STATUS
ch07.xml decreased to 26%.

Book Russian. Translated two paragraphs. Corrected typo in HACKING.

* src/en/book/ch07.xml
(svn:keywords): Fix a typo in the warning. This is a followup to r2070.

Stop setting execute permission on installed documentation files.

* src/tools/Makefile.base-vars (INSTALL): Remove, replacing with...
(INSTALL_DATA, MKDIR): ...these more specific variants.

* src/tools/Makefile.base-rules: Throughout, use new command variables.

* src/en/book/ch07.xml
(svn:keywords): Document fixed-length keywords, including a warning
I thought up and confirmed regarding the possibility for file corruption.

Remove some TODO items moved to Trac.

Book Russian. Translated three paragraphs and table.

Book Spanish. Translated three paragraphs.

* src/en/book/ch07.xml
(Peg and Operative Revisions): Re-work the opening words of this
section, plus fix a little typo elsewhere in the section.

Book Spanish. Finished the revision -against the original book- of the foreword.
However, there are some TODOS that are likely to go on as they are.