This introduces a few basic color codings to make the terminal output more
readable (and more fun). Rclone's standard --color flag is supported.
(AUTO|NEVER|ALWAYS)
Only a few lines have colors right now -- more will probably be added in
future versions.
Before this change, bisync handled copies and deletes in separate operations.
After this change, they are combined in one sync operation, which is faster
and also allows bisync to support --track-renames and --backup-dir.
Bisync uses a --files-from filter containing only the paths bisync has
determined need to be synced. Just like in sync (but in both directions),
if a path is present on the dst but not the src, it's interpreted as a delete
rather than a copy.
