Fixed timer, reward always random,multipleloading

Replaced the timer code again with a normal timer, problem occured
because of a thread issue. Needed to force use the IU thread or
something. Resetscreen method reset imageURLs now. Reward stage is now
set load random reward. If you only have 1 you will always load that
one. All elements will now be loaded on the screen during appropriate
stages except for reward stage. Need more options for actions to define
different functions and signals still load 1 even though they are
looped. This has to do with how i use timedElement to load the signal.
Moved a simpel method to the bottom.