-=head2 CanBookBeIssued
-
-Check if a book can be issued.
-
-my ($issuingimpossible,$needsconfirmation) = CanBookBeIssued($borrower,$barcode,$year,$month,$day);
-
-=over 4
-
-=item C<$borrower> hash with borrower informations (from GetMemberDetails)
-
-=item C<$barcode> is the bar code of the book being issued.
-
-=item C<$year> C<$month> C<$day> contains the date of the return (in case it's forced by "stickyduedate".
-
-=back
-
-Returns :
-
-=over 4
-
-=item C<$issuingimpossible> a reference to a hash. It contains reasons why issuing is impossible.
-Possible values are :
-
-=back
-
-=head3 INVALID_DATE
-
-sticky due date is invalid
-
-=head3 GNA
-
-borrower gone with no address
-
-=head3 CARD_LOST
-
-borrower declared it's card lost
-
-=head3 DEBARRED
-
-borrower debarred
-
-=head3 UNKNOWN_BARCODE
-
-barcode unknown
-
-=head3 NOT_FOR_LOAN
-
-item is not for loan
-
-=head3 WTHDRAWN
-
-item withdrawn.
-
-=head3 RESTRICTED
-
-item is restricted (set by ??)
-
-C<$issuingimpossible> a reference to a hash. It contains reasons why issuing is impossible.
-Possible values are :
-
-=head3 DEBT
-
-borrower has debts.
-
-=head3 RENEW_ISSUE
-
-renewing, not issuing
-
-=head3 ISSUED_TO_ANOTHER
-
-issued to someone else.
-
-=head3 RESERVED
-
-reserved for someone else.
-
-=head3 INVALID_DATE
-
-sticky due date is invalid
-
-=head3 TOO_MANY
-
-if the borrower borrows to much things
-
-=cut
-
-# check if a book can be issued.
-