Shortcut CMD+ARROW_DOWN on MacOSX

[Bouke]

Summary:
The shortcut CMD+ARROW_DOWN on the Mac should open files and directories, instead of transferring files.

Description:
On Mac OsX, when the CMD and ARROW_DOWN key are pressed, the selected file will be downloaded. Everywhere else on the Mac, CMD+ARROW_DOWN is used to open the highlighted file or to enter the highlighted directory. I've made this mistake numerous times, to accidentally enqueue thousands of files from the server, when I just wanted to open a directory. This is particularly frustrating because on the Mac, the interface basically hangs while transfers are in progress, so there is no way to stop it.