#122 created the classes JasperReportDownload, JasperDownloadParametersGenerator and JasperDownloadDataSourceGenerator
#122 added deprecated tag to JasperDownload
#122 moved the classes JasperDownloadDataSourceGenerator and  JasperDownloadParametersGenerator into JasperReportDownload and renamed them. Added Javadoc.
#122 created BackgroundTaskDownload
#122 cancelation of a BackgroundTaskDownload
#122 added comments to JasperReportDownload
#122 changed execution order. The datasource is generated first then the parameters are generated.
#122 surrounded the generation of the datasource and the paramters with a try-catch.
Merge branch 'feature/122-enhanced-jasperDownload' into dev