Scripts/reports: minor exts to pull-aafds-logs.sh

Minor extensions to scripts/reports/shibbolethDS/pull-aafds-logs.sh
* allow passing "--dry-run" to be passed to parser script
* catch failures of wget and parser script and report (and delete incomplete download)
Scripts/reports: add DS host option to log parsers

Add an --ds-host <hostname> option to log parsers (parse-aafds-logs.pl
and parse-ds-logs.pl) to allow parsing logs from a remote system and
correctly store the hostname of the actual DS handling the session.
Scripts/reports: pull-aafds: remote DS host name

Add the hostname of the remote DS host to the configuration file
pull-aafds.conf and pass that to the log parser in pull-aafds-logs.sh
Scripts/reports: generic pulling of remote logs

Add a generic script for pulling remote logs (superceding the
specialized pull-aafds-logs.sh script)

Configuration is defined in pull-remote-logs.conf where each line consists of:
* LOG_ID - a short ID of the configuration entry (used to name a directory where the remote logs from this source will be stored)
* REMOTE_DS_HOST - the name of this DS host (to be passed to log parser scripts and stored in the database as ds_host)
* LOG_TYPE - currently either AAF-DS or Tuakiri-DS (selects which log parser to use - either parse-aafds-logs.pl or parse-ds-logs.pl)
* URL_BASE - the base URL where to fetch logs from (must support directory listing)
* USERNAME - username to use for authenticated access to the remote URL
* PASSWORD - corresponding password

The script pull-remote-logs.sh for each of the line in the configuration file:
- fetches the directory listing and parses it for file names (assuming an Apache-generated index page)
- for each file, checks whether the file already exists in the local directory
- if not, fetch the file and pass it to the local parser
Scripts/reporting: fix typo (URL) in sample conf

Fix typo in sample URL in pull-aafds.conf, the sample config file for
pull-aafds-logs.sh
Scripts/reporting: change base dir for remote logs

In pull-remote-logs.sh, change the base directory used for storing
remote logs - to "$DIR_BASE/../remote-logs", allowing to have the script
in "bin" directory and logs in a sibling directory.