Version Control With Subversion Source

Change the spaces between the deleted and added filename columns to
_'s to make the columns easier to visually line up.
Sort deleted and added filenames and directories by the lowercase
versions of their basenames instead of their complete path, which
makes finding files that were moved into different directories
easier to match up.
Patch contributed by Peter Gervai <grin@...>.

* doc/book/book/ch07.xml:
s/svn-load-dirs.pl/svn_load_dirs.pl/g.