Version Control With Subversion Source

be relocatable, and fix an awk command.

* Makefile.in
(BOOK_TOP): New var.
(BOOK_DIR, MDOCS_DIR, doc-book-html, doc-book-pdf, doc-book-ps,
doc-misc-docs-html, doc-misc-docs-pdf, doc-misc-docs-ps): Use it.

* doc/book/Makefile
(BOOK_DIR, MDOCS_DIR, XSL_DIR, RUN_FOP): Use BOOK_TOP variable.

* dist.sh
(WC_VERSION): Adjust awk command for new 'svn status' output.