Suppress output clutter in `trash` command

Previously, the `trash` command would print out path information of the items it was deleting. This was unrelated to the verbose log messages `trash` would print when using the '-v' option, and cluttered the screen with long, AppleScript-style paths to the item in the ~/.Trash directory. For example, when trashing '~/Desktop/delme', `trash` would print:

    folder delme of item .Trash of folder mtorok of folder Users of startup disk

This update suppresses the above messages by redirecting the output the `osascript` command to delete the file to `/dev/null`.

Again, this should not change any of the intentional messages `trash` prints, either in normal operations, or in verbose mode.