Fixing lag issue

Someone mentioned lag due chatscript:
http://developer.roblox.com/forum/updates/8391-new-core-guis?start=120#91762

I found where it comes from, and fixed it.
The reason I use "> 0.1" is for rounding errors, and the fact we're substracting by 0.2, so the result will always be 0.
Update ChatScript.lua
Merge pull request #55 from einsteinK/patch-3

Fixing lag issue