Bot aim improvements

Here it is the list of the meaningful commits (7 commits filtered out):

• 58a8604c further improve aim of skilled bots by removing simulated aim lag: it's kind of redundant (aim is already lagged in another way) and wastes a lot of fields
• 789dadd6 remove weird zoom logic with the vortex
• c800330f increase the amount of error induced to the bots aim with skill < 10, make it less intense vertically and when bot is not aiming at any enemy and a bit more randomized in time
• dc1d977b fix think rate formula giving exaggerated importance to bot personality values of "aithink" (set in bots.txt)
• aea5c72f fix aim think rate lower than expected (7.5 instead of 10 fps) for high skill bots due to extremely small precision errors
• 4ae6e27e improve aim by refactoring max fire deviation formula, now more accurate and scalable on any distance
• ee2f4178 improve bots aim by requiring they aim at the target (with some tolerance) before starting to shoot (bot_ai_aimskill_firetolerance is now enabled by default). It fixes bots often missing the first shot right when they get a new target if they were aiming in a different direction
• 4541e69d fix bots sometimes firing in the opposite direction if bot_ai_aimskill_firetolerance is on
• 6004621b improve remote rocket detonation. It fixes bots detonating rockets prematurely and dealing less damage.
• bfebc940 improve rocket guide with the devastator
• 74ab8f6a fix bots randomly refusing to shoot with the devastator