Update yahoo/finance/yahoo.finance.balancesheet.xml

Use a wildcard search when matching for report type and default reporttype to 'bs'. E.g y.context.table will be 'balancesheet' for a query with a 'USE ... AS balancesheet' but 'yahoo.finance.balancesheet' for a query direct from yahoo datatable source.
Conflicts:
	yahoo/finance/yahoo.finance.balancesheet.xml