Swapped LOX and LH2 tank sizes in the US cell.

For GH #9.
Added descriptions for US tanks and Fuel Cell (#9)
Added LS description to US Radial Oxygen (#9)
Updated Elektron (US, GH #9)

- Updated to TAC generators.
- Updated to match discussion on GH #9. Previously it was only
  using 4litres of water per day.