[MCPE-2382] Stone sword deal damage as same as Iron one

I tested on my world. I use 3 hits to kill zombie and 2 hits for skelleton with stone sword as same as the iron one.

Linked issues

Mobs have wrong health, try to hit mobs with nothing, everytime you hit mobs, you'll get it half heart damage.

The problem is with the hostile mobs not with the swords

Cleaning up all the old issues - please reply if this affects 0.9.3.