Fix path completion when outside of /

Signed-off-by: Raul Gutierrez S <rgs@itevenworks.net>
Fix autocomplete when the path isn't the 1st param

Signed-off-by: Raul Gutierrez S <rgs@itevenworks.net>
New shortcuts for cd

cd is equivalent to cd /.
cd - is equivalent to cd $previous_path.

Signed-off-by: Raul Gutierrez S <rgs@itevenworks.net>