Added Keyboard Controls.

Using Arrow-Keys, as requested in deplicator/xkcdTime_atyourownpace#12
Using e.which instead of e.keyCode

Cause stackoverflow said so.
http://stackoverflow.com/a/6011119/2256700
Add Loading-Indicator, fixes deplicator/xkcdTime_atyourownpace#16

Also some #Loading-references were updated to use #LoadingImage
Merge pull request #18 from MaPePeR/arrow-keys

Arrow keys
Merge pull request #19 from MaPePeR/Loading-Indicator-#16

Add Loading-Indicator, fixes deplicator/xkcdTime_atyourownpace#16
Fixed FF slider, at least part of it.