Assorted item tweaks

Mine changes:

• Mines can be punted away by driving into them before they finish deploying
• Laying down Mines behind adds a long pause before deploy starts
• Forward Mine throws land much faster
• Mines no longer explode on a timer

SPB changes:

• SPB Rush item odds are longer affected by player count scaling
• A reticule is displayed on the minimap over SPB target

Thunder Shield changes:

• Thunder Shields can no longer be rolled while SPB is out.
• Thunder Shields can no longer be rolled if someone else is holding one.

Other:

• Grow can be cancelled early by holding down the item button. (Grow is weighted even harder toward the back than before to accommodate)
• Generic explosion spinout (everything except SPB) has been nerfed, now the same length as normal spinout.
• Certain items can't be rolled during the first 30 seconds of a match.
• Shrink is consistent 20 seconds for everyone affected, instead of varying depending on position.
• Hyudoro has a 5 second buffer every time its rolled before another can be given.
• New sound effect for lobbed item sniping (bananas, sinks).
• Some smoke effects are no longer translucent, to reduce lag.