Maven test related fixes

- Workaround for usage of symlink in P4 code.
  Should probably avoid using symlink and load as resource
  for benefit of buck also
  https://buckbuild.com/concept/buckconfig.html#project.allow_symlinks

- Netconf Active client test dependency fix

- NetconfControllerImpl has mutable static variable,
  clean up after tests which potentiallu touches them

Change-Id: If7a70357a04ccc7e36377301de080385190d2776
diff --git a/core/net/pom.xml b/core/net/pom.xml
index c13f997..1278433 100644
--- a/core/net/pom.xml
+++ b/core/net/pom.xml
@@ -134,4 +134,16 @@
         </dependency>
     </dependencies>
 
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-resources-plugin</artifactId>
+                <!-- Workaround for P4 test code using symlinks in git -->
+                <!-- last version which copies symlink target -->
+                <version>2.7</version>
+            </plugin>
+        </plugins>
+    </build>
+
 </project>