Merge pull request #112 from delta534/master

This should fix the server/client sync issues for the Certus Tanks.
ExtraCells 1.6.6b

-Fixed Import Bus Power Issue
-Performance Fixes on Certus Tank
ExtraCells 1.6.6c

-Battery now woorks like a redstone conrolled version of the energy cell
-Added further information in the Fluid Mode Selector