Rolled run_deltasync_tics into run_tics

Removed or commented out several printf debugging statements

Only remove commands clientside after all sync messages have been
processed

Servers now update sync whenever a TIC is run, not just at the end;
avoids off-by-one gametic problem (where gametic is X, but the state is
really X - 1 because command X - 1 ran in gametic X - 1)

Servers no longer run client commands multiple times; had to add a
"last_command_run" member to peer (and add a bunch of crap to p_tick.c)
to get this happening though :(
Fix persistent crash when loading save data

Restore client sync in the case of invalid delta data

Continuing to try and even out prediction