Fix - don't allow dead body of player to climb on the ladder

It was visible probably only locally.
Better visibility for warning about outdated AC version

Commit changes also masterserver URL to AC homepage in info related
to this warning.
fix directory search order

also clarify some log output
(thx grenadier)
added mandatory client log file

- a client will now write all os console messages to "clientlog.txt"
- at every game start, the log file gets rotated (with five old logs kept)
- commandline parameter "-N" can be used to limit the number of lines
  (after the lines are logged, the file is closed)
Fix switching from spectator to active team in bot modes

Before this fix player could switch from spectate to alive mode,
but he stayed in SPECTATOR team.
Note: 2 mouse clicks are necessary to player's spawn.