#252 loading the nas products from property file. this simplifies introducing new nas products
#252 appending dxf format to download file if format is dxf
#252 fee preview for points did not show correctly in fact of incompatible key names of the nas product. corrected the nas product key
#252 added json file with nas product descriptions
#252 changed title from nas dialog
#252 changed title from download to dxf download when format is dxf
#252 changed title for dxf download
#252 changed display name for NasProduct DXF
#252 changed name for combobox  Abgenart to Abgabeart in NASDialog
#252 added getter for billingInfo and billing products to BillingPopup class. This was necessary to reuse the configured product prices when calculating the NAS fee preview
#252 use the prices configured in the billing.json when calculating the fee for nas / dxf downloads
issue #252: minor changes

* minor text changes
* mandatory requestId for NAS
* change pre selection for "Abgabeart" combo box to "NAS (ohne
 Eigentümer)
 #252 removed double entry from bundle file

the second entry was introduced due a resolve of a merge conflict after
rebasing the feature branch to dev.
 #289 removed dxf format option in alkis datenausgabe
 #289 removed set title(null) in Butler2Dialog
#289 upgraded jcl-over-slf4j version
#252 billing for dxf product
#252 added new nas product dxf SW, added additional parameter for action server
#289 additional parameter for farb / sw ausgabe
#252 grau_RGB mode fpr sxf sw product