Replaces the different sleep() calls from the slime reactions for spawn() calls. Now you can't inject the same reagent into different cores generating runtimes.
Standarized some of the code of slime reactions, hopefully they won't be creating issues.
Removed the plasma bluespace slime reaction. It was so bad. SO BAD.
Merge branch 'master' of https://github.com/tgstation/-tg-station into SlimeReactions

Conflicts:
	code/modules/reagents/Chemistry-Recipes.dm
Merge pull request #2875 from Aranclanos/SlimeReactions

Slime reaction fixes.