bin/after_import: use new bin/make_backups
moved everything into /trunk/ to create the standard svn layout, for use with tools that require this (eg. git-svn). IMPORTANT: do NOT do an `svn up`. instead, re-use your working copy's existing files with `svn switch` (http://svnbook.red-bean.com/en/1.6/svn.ref.svn.c.switch.html).
bin/after_import: support turning off the end-of-import backup for imports that are not the full database
bugfix: bin/after_import: run backups/fix_perms right after the backup files are created to make them private
bin/after_import: usage: documented that it requires $version
added bin/after_import, which performs post-normalized-import actions separately from bin/import_all