Improved spreadsheets controller code.

Apllied the methods used in the Planetary Interaction spreadsheet to the other
spreadsheets to reduce coding and also improve readability.
Removed redundant and mistaken information from some spreadsheets.

- Removed the "Using prices from" text which was redundate since the dropdown
  menus keep the locatinons used in the current request.
- Removed the formulas because all spreadsheets had the ore mining formulas and
  even that was incomplete and outdated. Formulas may come back later