New PowerSystem: GregTech

As GregTech 5 has introduced its own E-Net - this could be useful :)

__Details__:
 - Each Voltage Tier has its own Consumer/Producer (like IC2)
 - Consumer will only consume 'full' packets (1A), so no energy gets wasted.
 - Producers will generate 1A at their Voltage, this applies to all Voltage Tiers
 - Balancing is based upon IC2, so 32 IC2-EU are equal to 32GT-EU @ 1A
 - The default size of the internal bridge buffer may be too small for Voltage Tiers
   above LuV, so the capacity should be adjusted in your configuration. ** 
 - Colorization of Consumer/Producer is not yet possible, it will remain always 'uncolored'


__Pending Improvements:__
 - Localization needs to be done for all languages except EN.
 - The Textures should be reworked by someone who's more talented in Graphics Design :)
 - Tile Colorization Support 
 - Add a way for PowerSystem Components to set the "minium required brdige buffer capacity" 
   (by adding it to TileEntityBridgeComponent, so each component could overwrite it if required)
   So the default Bridge buffer does'nt have to be huge, as the Bridge should'nt act as 
   some kind of Energy Storage/battery.