gnc:account-get-trans-type-splits-interval with an empty account list

[Mike Alexander]

The problem with the balance sheet report when there are no trading 
accounts in the book was due to the fact that 
gnc:account-get-trans-type-splits-interval in report-utilities.scm 
returns splits from all accounts when it is given a null account list. 
I didn't change this since I didn't have the time to follow all the 
paths that lead to this function, but it seems to me that this is 
wrong.  It causes functions like 
gnc:accountlist-get-comm-balance-at-date to compute a balance for all 
accounts when given no accounts.  What do others think?  Is this the 
correct behavior?

        Mike