Added 'saved' to translation
Navigate feeds using your arrow keys

left key = previous
right key = next
Also open next (or prev) content when curren is open

Also open next (or prev) content when curren is open when you are
navigating with the left and right arrow key
Removed trial code
Added CS translation + changed new additions

New translations are prefixed with a #, see remark of jan-battenfeld
Updated spacebar behaviour + added keycode

- Pressing "o" opens/closes an entry
- Spacebar opens the selected entry when using arrow key navigation.
When there is no entry selected the spacebar opens the first entry on
the page (as before)
Moved code to function

Left / Right and spacebar navigation moved to functions
Updated help section
Fixed JavaScript error
Merge pull request #209 from jicho/master

Added 'saved' to translation