Merge pull request #526 from chrox/master

fix kobo frozen when exiting koreader.

It doesn't work sensibly anyway. It should have taken a screenshot of the homepage of nickel. Instead it gives the last screen before koreader, which is the png-file of koreader. 
Just quitting the png-file and returning to Nickel home screen would be sufficient. No idea how to do that, though.

koreader_kobo.sh

@@ -14,12 +14,12 @@ export STARDICT_DATA_DIR="data/dict"
 killall -STOP nickel
 
 # store the content of the framebuffer
-dd if=/dev/fb0 of=.last_screen_content
+#dd if=/dev/fb0 of=.last_screen_content
 
 # finally call reader
 ./reader.lua /mnt/onboard 2> crash.log
 
 # continue with nickel
-cat .last_screen_content | /usr/local/Kobo/pickel showpic
-rm .last_screen_content
+#cat .last_screen_content | /usr/local/Kobo/pickel showpic
+#rm .last_screen_content
 killall -CONT nickel