Bot AI updates

Notable fixes / improvements:

• 6ee9b6d6 Bot AI: clear aim target upon death. It fixes #2012 (closed)
• ae17c0fd Bot AI: evade dangers like trigger_hurt and lava by aligning to the ideal route if off-road (also pits are now counted as dangers). It improves movement control on dangerous paths, e.g. on mentalspace bots don't fall anymore after jumping from the central platform to the base.
• 0dbe060b Bot AI: while targetting an enemy try to pick a new target after some seconds (bot_ai_enemydetectioninterval_stickingtoenemy) rather than when health is lower than 30. Fixed description of bot_ai_enemydetectioninterval
• 6ae33131 Bot AI: make bots faster by refactoring bunnyhop algorithm
• abdc0aa8 Bot AI: fix bots attacking with harmless blaster secondary when they have okmachinegun or okhmg
• 465645cb Bot AI: fix bots sometimes needlessly jumping from ledges
• a2f0b94d Dinamically test and create links from waypoints to items every time a bot heads to an item since creating all the links for all items when a bot joins is very expensive; it fixes #2048 (closed) "Adding bots causes a server spike"

And other minor fixes / optimizations