[NX-19] Add a getter for a log configuration file given its name

Logging configuration dir can be configured via system properties so we ask the manager to resolve the file

Signed-off-by: Alin Dreghiciu <adreghiciu@gmail.com>
[NX-19] Implement reading/saving of logback-dynamic.xml

Signed-off-by: Alin Dreghiciu <adreghiciu@gmail.com>
[NX-19] Fix license header

Signed-off-by: Alin Dreghiciu <adreghiciu@gmail.com>