bugfixes:
  - ce_dldp - tag named data of a xpath is unnecessary for old software version to find a element from xml tree, but element can not be found with 'data' tag for new version, so remove.
  - ce_dldp_interface - tag named data of a xpath is unnecessary for old software version to find a element from xml tree, but element can not be found with 'data' tag for new version, so remove.
  - ce_vxlan_arp - override 'get_config' to show specific configuration.
  - ce_vxlan_gateway - override 'get_config' to show specific configuration.
  - ce_vxlan_global - Network_cli and netconf should be not mixed together, otherwise something bad will happen. Function get_nc_config uses netconf and load_config uses network_cli.
  - ce_vxlan_tunnel - Network_cli and netconf should be not mixed together, otherwise something bad will happen. Function get_nc_config uses netconf and load_config uses network_cli.
  - ce_vxlan_vap - tag named data of a xpath is unnecessary for old software version to find a element from xml tree, but element can not be found with 'data' tag for new version, so remove.