WorkItemdefinition changes to support META-INF (logical) and the default location for this file in Business Central in BPMS6 beta

 1. Made the workitemdefinition also load from /WorkDefinitions.wid (as this is the default in BusinessCentral in the BPMS6 beta)
 2. Made the system catch Exception, as otherwise some of the default tasks may prevent a successful startup. Errors are still logged.