added backups/*retention_policies*/ with retention policy files for each partition

backups/README.TXT: renamed to retention_policy to match the naming convention of the retention policy files in the various partitions

/README.TXT: to back up the local machine's hard drive: also exclude *-files indicating the (differing) retention statuses of the partitions involved

lib/tnrs.py single_tnrs_request(), bin/tnrs_client: use_tnrs_export: default to False because this mode uses incorrect selected matches (vegpath.org/issues/943), and the JSON mode that fixes this is now available

bin/tnrs_db: tnrs.tnrs_request() call: explicitly set use_tnrs_export=True so that this continues to work if the default value is changed

bugfix: lib/csvs.py: JsonReader: need to pass col_order to row_dict_to_list_reader

config/VirtualBox_VMs/vegbiendev/README.TXT: ~/Documents/BIEN/vegbiendev.2014-2-2_1-07-32PT.+VirtualBox_changes/: renamed to vegbiendev.2014-2-2_1-07-32PT.VirtualBox/ to make clear that this is the VirtualBox version of vegbiendev

bugfix: lib/tnrs.py: JSON output: need to stringify arrays so they match what is output in TSV-export mode

lib/csvs.py: JsonReader: added support for values that are arrays

lib/csvs.py: MultiFilter: inherit from WrapReader instead of Filter to avoid needing to define a no-op filter_() function