Bot's Acid Evasion & Item Auto Pickup

As the title said, this mod gives bots 2 features that the original L4D2 doesn't have. "Acid Evasion" is bot's ability to immediately run from acid when it falls on the ground. Normally bots love to stay until they get hit by acid before they start to move. Even some bot mods also still have this bot's behaviors though they could make bots avoid acid more frequently. But on this mod, they will have like 90% chance to avoid acid! The rest 10% is when they're unlucky to get cornered or run in wrong way, but this rarely happens.

As for "Item Auto Pickup", this makes bots pick items automatically when the items is in the radius of auto pickup. This can solve problems with bots refusing to pick items due to bot navigation error on some custom campaigns.

Here are the features in "bot acid evasion.txt" cfg:
1. Acid Evasion: The main feature to enable bot's acid evasion
2. Acid Escape Timer: The sub feature of "Acid Evasion" that controls how long the bots will run away from acid.
3. Acid Standby Timer: The sub feature of "Acid Evasion" that controls how long the bots will remain standby on one place to wait until the acid disappears.
4. Item Auto Pickup: The main feature to enable bot's auto item pickup.
5. Item Auto Pick Range: The sub feature of "Item Auto Pickup" that controls the range of item auto pickup. The value is the range of the auto pickup.
6. Item Auto Give: Bots will automatically give items to players simply when players in in close range (melee range). The value affects which items to gve (first aid kit only, or with throwable, pills & primary guns).

As the settings of "Acid Evasion" have to be set correctly, here's the simple tutorial of how to configure it:
-  "Acid Escape Timer" makes bots run in the duration of the value of this feature & at the same time triggers standby state, this should be set lower than the value of "Acid Standby Timer" to prevent unwanted bugs.
-  "Acid Standby Timer" makes bots move again by the end of the duration, so it must be set higher than "Acid Escape Timer" to prevent unwanted bugs.
- Set the value of both sub features with the difference of 1 or 2 seconds. For example: "AcidEscapeTimer 3", "AcidStandbyTimer 5"

With this mod, you'll have better bots at avoiding acid & at the same time very kind bots that will voluntarily give you their items when you don't have them :D .

Notes:
- Some known bugs on "Item Auto Pickup" feature:
--- Bots can duplicate items sometimes (imagine 3 bots pressing E on the same item at the same time).
--- Bots can always pick throwables when they're close to the throwable spawn spot, so basically bots become grenadiers or grenade suppliers with unlimited supplies if they camp near throwable spawn spot.
--- "Item Auto Pickup" also makes bots prefer T2 guns over T1 guns, theywill switch to T2 immediately when they're close to it even if the T2 gun is low of ammo or empty. This will be fixed later. & you can also set "Item Auto Pickup" to 2 to make bots pick item automatically when players hold TAB button.