Blob Tweaks

 * Made the mining shuttle one way during blob. 
 * Increased players per blob and decreased blob count to win.
 * Changed the health value of the blob spores.
 * Blob gamemode will give the blob core a resource rate of 2, random event blob cores will get 1.
 * Raised the amount of time that has to pass before the blob random event occurs.
 * Increased the difficulty of expanding into space.
 * Added a player limit to the blob gamemode.
 * Removed density from shield and other variables which are set in the abstract blob.
 * Deleted spores after they die.
 * Disabled random blobs in the blob gamemode.
 * Double'd the blob spore's health.
 * Blobs can expand into space again but it will be harder to do than on a space tile.
 * Dead robots will be gibbed in their blob_act() as their bodies will block the blob.
 * Reduced the damage the blob takes from explosions, and increased the brute resistance. Blobs main weakness is fire, not force.
 * Disposal units will now drop their contents onto the floor when deleted, such as from a blob attack. Fixes #963