Updated documentation to match recent enhancements and additional models. Note that the description of the bvapec model is now included along with the bapec model, not in a separate file.
Fixed a plotting bug. The green line marking 0 or 1 in the res, ratio, chi etc. plots did not go all the way across the plot if a rescale was done so that only part of the x-range of the data was included. Note that a rescale to start at an x-value below the initial data will not draw the green line for the x values below the start of the data.