Added classes to all input fields
Added classes to all input fields so they would be easier to find with jQuery.
This way, we don't need to search based on [name=], but can instead reference them directly (and dynamically).
Fix the calculate methods (because I broke them)
Moved the financial functions in the FC.calculate object
Added some comments to clarify variables (or ask for clarification)
Temporarily removed verification (strictly speaking, the server is already doing this, and we probably want the end-all calculate function to get these varaibles from the server, so we can calculate stored values directly).
I'm sorry if I broke anything; please let me know.