FMSLogo Code

This time, really fix bug #1661229. The previous "fix" was very buggy.

Correct some of the tests after bug #1661229 was fixed.

Fix bug #1661229; MDSETITEM now throws an error when given bad inputs.

Fix bug #1652783; Out of bounds index errors in ITEM are now recoverable.

Fix bug #1661226; MDARRAY now throw an error when it inputs anything other than a list.

Fix bug #1661228; MDSETITEM now throws an error when the indexlist input is not a list.

Make the "clean" target remove 3dmovie.gif. I accidently released this with FMSLogo 6.18.0 because "gmake clean" did not delete it.

Make tetrads.lgo a little easier to hack by choosing a random item from the :gameshapes array, instead of assuming that there are seven items in the array.

This came up during at the Bellevue Boys and Girls Club. A student had correctly removed all shapes execept one from the :gameshapes array, but then the program didn't work because a different part of the code assumed that there were seven elements. Since I want to encourage hacking, I am making the rest of the code more robust.

Fix bug #1803975; Output from DEBUGWINDOWS is now internationalized.

Fix bug #1803793; The string "N/A" for Palette in Status window is now internationalized.