BUG-2459: Fix netconf-monitoring not reusing JAXB context

JAXBContext can be freely reused, so cache it, as it has significant
footprint in testing tool.

Change-Id: If2f53b9dfd4a1d30390580fd800aa2f5eb4e2b72
Signed-off-by: Robert Varga <rovarga@cisco.com>
BUG-2477 Remove unused pax-exam plugin from netconf-it

+ remove version depend. in for pax-exam in adsal/commons/integrationtest

Change-Id: Ib077603f23072a1c56f6d39c51ad29bb7d7d8ad7
Signed-off-by: Maros Marsalek <mmarsale@cisco.com>
Signed-off-by: Vaclav Demcak <vdemcak@cisco.com>
Merge "BUG-2459: Fix netconf-monitoring not reusing JAXB context"
Merge "BUG-2477 Remove unused pax-exam plugin from netconf-it"