hopefully fix bug #523, file extension association

merge for the win

caught two frontend warnings

convert HAVE_NETSERVER to check for file existance, so that it's easier to provide missing servers

convert HW_DEV in ifdef DEBUG clauses

fix portal/hammer interaction, ban freezer from portal

keep hogs from sliding while they are being frozen

Make hogs thaw only on enemy turns, make timebox counter decrement only on your turn, adjust knock for frozen hogs, increase damage on frozen hogs, make freezer fuel only reduce when not adjusting angle.

Call act as if attack ended on last shot if switching while in mid multi-shoot. Thanks to AI for discovering this.

add neglected merge