Push sparks lag to GC this should greatly reduce lags.

Test: 20 emitters shooting for 10 minutes. No lag. Along with other various tests.

git-svn-id: http://tgstation13.googlecode.com/svn/trunk@5757 316c924e-a436-60f5-8080-3fe189b3f50e
Made the effects of EMP pulses get garbage collected. Less lag on the singularity (around 20 effect del per 5~10 seconds)
SecHUDs and medHUDs (including pAIs and odyssesus) won't create a fuckload of images per tick and then disposal them, lagging like retards.
Now each human will have a list of HUD images, that will be refreshed if it's required, say, a medic walking near you with a medHUD will refresh both medical images.
The list, called hud_list, uses seven defines for all the images, defined in the __DEFINES.dm

I also added a check for not rounding the health bar if the pacient it's dead, fixing some issues with showing dead people in critical or with possitive health.
Removed the auto-update from exosuit fabricates. They were huge lag generators, loops inside of other loops each process() tick.

This will help to reduce lag.
Removed the commented out code from the auto update options of exosuit fabricators.
For this reason, the exosuit fabricators will be removed from the process() list at roundstart.
(cherry picked from commit 8e191ebac99dc1f93b1b03a89784212f31f4b985)
Changes on how some simple hostile mobs search for targets, they now make a list of mobs at sight with the heareable() proc and add the mechs of a new global list instead of checking all the atoms in a radius of 21x21.
The new global list is called mechas_list, it contains all the mechs (sadly the 8 mechs of centcomm are added to this list, just to avoid problems with other servers with different maps)
Clowns, goats and spiders still use the old way to track targets (the view() proc).

The goal of this commit is to reduce lag, it will be really noticeable on the carp migration event, they should be 70% less laggy.

git-svn-id: http://tgstation13.googlecode.com/svn/trunk@5820 316c924e-a436-60f5-8080-3fe189b3f50e
Compile fixes.
Runtime fixes, tweaks.
Merge pull request #2969 from Spamcat/antilag

/tg/'s antilag patches