Added displaying Sales Invoice mark/cancel information
1. Renamed Posted Sales Invoices Report to Posted Sales Report
2. Added Sales Returns to Posted Sales Report
Merge branch 'add-sales-returns-to-posted-sales-report'
Added Search Sales Returns function
Merge branch 'add-search-sales-returns'
Added basic Bad Stock Return screens
Added posting of Bad Stock Return
Merge branch 'add-bad-stock-return'
Updated version to 1.9.0