add: yb_chat_percent, yb_camping_time_[min/max], yb_danger_factor[min/max], yb_chat_percent cvars
fix: possible crash with difficulty 0
fix: debug_goal should not be used as last history
fix: startup on old hlds, because of missing pfnGetFileSize
fix: crash with out-bounds read
change: again tweaked some aiming code
change: player avoidance code so bots will jump less when stuck
change: max followers is just /4 of max players
refactor: redone distance between vectors
refactor: remove magic numbers in graph.add function