Bunch of personal tweaks to AB experience.

• Moves bob's robots past Chemical science
• Moves Crawler versions of requester, provider and buffer chests to Logistic science tier, but makes Crawlers more expensive and drastically more power hungy (they are massive bots carrying stacks of items after all). Crawler Logi bots are changed to use bob's robot parts because I felt they are otherwise too trivial to build. Crawler contructors aren't changed, but I think there is a balance issue that might require to be fixed - they might depend on higher tier stuff to build the zone expanders)
• Makes sniper and plasma turrents not completely useless (they remain vastly more expensive to run vs 1.1 versions, they are not actually detrimental anymore)
• Buffs bob's burner heat sources a little bit
• makes mini trains fully available in Automation tier, without doing bunch of other weird changes (if you REALLY want to hit that 1000x I guess)