add art for 5 new sprites, improve handling of large numbers of sprites, fix wait for click

We have 5 new sprites!

The k-1 freeplay level was updated so that you can have all 11 sprites active at the same time.

I also fixed a long-standing issue with the text dropdowns. The strings for each actor number are now dynamically generated, getting rid of the silly strings that said "actor 1", "actor 2", etc.

Found a problem with the wait() block when "click" was selected. I think it broke when Brian cleaned up the use of "random" - this was one more case where we needed an exception (like "hidden"). I changed the block to use the value of "click" (previously it just assumed click with the value with 0 seconds) and added that value to our exception list for "random".