fix: lib/sh/util.sh: stderr_matches(): usage: documented that this may require benign_error=1

fix: /README.TXT: Mac backup: exclude ~/VirtualBox VMs/Ubuntu/Ubuntu.vdi, to avoid it being re-uploaded twice each time, due to an rsync verification error (https://projects.nceas.ucsb.edu/nceas/issues/907)

bugfix: lib/sh/db.sh: pg_cmd(): updated for new echo_vars log_level

fix: lib/sh/db.sh: pg_schema_exists(): display the function name so it's clear which function is running the psql commands

fix: lib/sh/db.sh: pg_schema_exists(): don't use log++ because it hides the command that produces the benign error

/README.TXT: changed "then rerun with l=1 ..." to "then review diff, and rerun with `l=1` prepended" to ensure that user reviews diff before syncing

/README.TXT: to synchronize a Mac's settings with my testing machine's: removed separate step to upload just the VirtualBox VMs, because that is now part of the main upload

fix: /README.TXT: to synchronize a Mac's settings with my testing machine's: need to sync VirtualBox VMs with inplace=1 because they are very large files

web/links/index.htm: updated to Firefox bookmarks: Ubuntu 14.04 upgrade: rsync: documented that this breaks use of ~ to reference the remote user's home dir

/README.TXT: to back up the version history: back up first on the local machine, because often only the svnsync command gets run, and that way it will get backed up immediately to Dropbox (and hourly to Time Machine), while vegbiendev only gets backed up daily to tape