Threads are now removed after every "inner" step. Any thread that
reaches its DONE conditions is immediately removed instead of requiring
an extra step to remove it. As such tests that check the number of
threads have been updated to consider this.
Checks for
- monitor types set correctly (all 4)
- monitor visibility set correctly
- monitor threads not running if not visible
- monitor positioning imported
- monitor width/height for lists
- custom monitor slider range
- sprite specificity
