Some small fixes

1) Removes double percent signs (%%) in mutations since they are no longer needed for proper formatting. (And are in fact causing problems when they both appear in the descriptions).
2) Fixes glare to work again properly.
3) Adds a sanity check to the movecost functions. This won't stop shopping carts and tables from appearing in walls, but it will at least stop things from using them to walk through them!
4) Fixes #3532 
5) Fixes #3513