added rsync:no
remove aggr command
symlink_mode is obsolete

Ignore the mode on a symbolic link altogether. When creating a link,
use the default umask.
updated Changelog
select default synctool_cmd and pkg_cmd
added option --numproc= to all of these
added docs in markdown
added chapter4 in markdown
added section numbers
documentation is now in markdown
Merge branch 'markdown' into dev60
Documentation is now in markdown.
Pretty neat, much easier to maintain and the resulting web pages look
practically the same because of the synctool_doc stylesheet.