Fixed show_score = False

The score should now be hidden when global show_score is set to False.
The score is also now shown to 1 decimal place. However, it may be best
to move from a percentage format to a score/trials format.
Added skip_training global

When set to true the experiment will skip the training stage and go
straight to part 2. This is just for testing purposes – will remove
this later.
Updated saveLogData() for communication

saveLogData() now saves the subject ID and writes separate log files
for each subject.