Various changes and fixes: Added report, etc. Tests pass.

* reworked and used TrsrDB::expand_ids more tightly
  * account item selection in TrsrDB::make_transfers
  * web_auth / User relation for coming HTTP interface
  * income and target inter-relations between TrsrDB::Credit and TrsrDB::Debit
  * Transfer note
  * reactivated enforceFixedCredit to take effect unless _temp table is empty
  * added CreditsInFocus and Report views

t/schema.t

@@ -49,7 +49,7 @@ while ( my ($num, $month) = each %months ) {
         billId => "MB$yy$num/john",
         debtor => "john",
         targetCredit => 1,
-        date => "16-05-01",
+        date => "$yy-$num-01",
         purpose => "Membership fee $month",
         value => 600
     });