#231 CTF: fix problems from first testing

[sjtsp2008]

fix (the simple) issues that bluelads discovered during first test of CTF
1) says wrong player dropped flag, after second player picks up
2) attacking causes real damage (just need to say "please dont attack"
3) thumb needs to explain basic idea better
4) thumb distributes some arrows after "play"
5) thumb should not let player "stop" twice in a row, nor "play" while playing