Changes to the Home Heat Loss Calculator

The calculator gets used several hundred times a day, so I thought some little cleanups were in order. 

Here is what changed and what did not..

- No algorithm changes were made, so the answers it produces are exactly the same as they were.

- Made a lot of formatting changes to make it more compact and easier to read.

- Added a plot to show at a quick glance how the heat losses of ceilings, walls, ... compare and which dominate.

- Added a Title field to make it easier to keep track of different runs -- especially printed ones.

- Put in some printing pagination to organize printed copies better.  You can probably print pages 2, 3, 4 and avoid printing all the boilerplate.

- Changed the CO2 emissions for electricity as a fuel from 2.2 lbs/KWH (typical of coal generation) to 1.5 lbs/KWH (average US generation).