Added Admin Feeder

https://github.com/CovertJaguar/Railcraft/issues/296

Implemented Admin Feeder
-Provides unlimted charge to the system by setting it's ChargeHandler capacity to full.

Also added localization lines for en_US
CovertJaguar/Railcraft-Localization#236

From botched pull request: https://github.com/CovertJaguar/Railcraft/pull/318