Budget report

[Phil Longstaff]

The budget report is my current itch, so I've been upgrading it.

My latest change is to provide more control over the columns.  To do this, the 
top level creates a scheme list where each element controls a set of 
budget/actual/diff columns:
  - if an element is a number, that is the period (origin 0) for the set of 
columns
  - if an element is a list, the list contains period numbers to be grouped 
and accumulated for the set of columns
  - if an element is 'total, the set of columns contains the total.

For a monthly budget, the current budget report is created by the list '(0 1 2 
3 4 5 6 7 8 9 10 11).  I'm looking at using '((0 1 2 3 4 5) 6 7 (8 9 10 11) 
total) which will give me Jan-Jun, July, Aug, Sep-Dec, Total for the year.  
This allows it to fit on my screen.

To make this more readily available, I think the proper thing to do is add a 
new tab to the options to allow the user to set up the columns.  Eventually, 
besides a "diff" column, a "percentage" column would be useful.

Maybe this is just leading towards ideas for a complete report rewrite where 
the user can design his/her own reports with general columns and rows.

Phil