Fix a few memory leaks in execute_cmd

Also, clean up the code by using common exit path.
Draw shot tracks

So it's clear who's shooting.
Optimize pattern and font selection in draw_stats

Create the pattern just once for all robots. Likewise with the font.
More comprehensible and compact stats
Reloading shown in stats
Allow setting of robot name
Fix includes with incorrect keywords

Should be #include, not #import. But they're not needed anyway, just kill
them.
Fix variables declared in .h files

They have to be extern and declared in a .c file.
Fixed screen size

There was an empty unused space between battlefield and stats.
Ranking

Display ranking when the game finishes.
Fix buggy boundary check
Fix buggy scanning algorithm

Enemies under angles near 0 and 360 might not be detected.
Score counting
Score ranked game

Enabled by default, -t to switch to time ranked game.
Dynamic adding of robots
Fix crash when a robot dies before start

We used live_length == 0 to distinguish already ranked robots, use -1
instead, so robots can have zero life length.
Allow limited communication before game starts

Useful for setting of a robot name.

Note that this changes the communication protocol. The clients need to be
rebuilt (no source code changes required).
Better name handling

Preserve spaces, do not print names in bold.
clients: allow manual init
More precise life time counters