Hammer changes/fixes: honor extra-damage (
issue #975), round up damage, do correct damage when being spammed in infinite-attack mode
oops. melon pieces need friction and elasticity to bounce right.
Fixes to 10760 to reduce desyncs on checkers and better heat my room during long dark winter nights
Put diagnostic message into log when quitting due to end of input in demo replay mode
just disable landpixels w/ blurry land instead. the mask can be helpful for debugging at least.