Rewrote GameLoader to just Loader

The original idea behind putting game instances into their own AppDomains
was so that game assemblies could be swapped while the bot would still be
running. It seems that (at least with Mono) even though the AppDomains
containing assemblies are unloaded, they're still kept in memory, making
all this extra work pointless.
It now scans for assemblies and loads them all at once on startup.
Implement new changes from the base class