Better error management when creating bookkeepin entries

htdocs/accountancy/class/bookkeeping.class.php

htdocs/accountancy/journal/bankjournal.php

htdocs/langs/de_AT/admin.lang

htdocs/langs/de_CH/stocks.lang

htdocs/langs/en_US/languages.lang

htdocs/langs/es_CL/companies.lang

htdocs/langs/es_CL/orders.lang

htdocs/langs/es_MX/admin.lang

htdocs/langs/es_MX/products.lang

htdocs/langs/fr_CA/admin.lang

htdocs/langs/fr_CA/products.lang

htdocs/langs/km_KH/accountancy.lang

htdocs/langs/km_KH/admin.lang

htdocs/langs/km_KH/agenda.lang

htdocs/langs/km_KH/banks.lang

htdocs/langs/km_KH/bills.lang

htdocs/langs/km_KH/bookmarks.lang

htdocs/langs/km_KH/boxes.lang

htdocs/langs/km_KH/cashdesk.lang

htdocs/langs/km_KH/categories.lang