Allow execution of shell IT tests in parallel in forked VMs

Try 100 ties to find free port for remote server during execution of IT
tests in shell to allow them to run in parallel and avoid port conflicts.

community/shell/pom.xml

@@ -59,12 +59,6 @@ the relevant Commercial Agreement.
 
   <build>
     <plugins>
-      <plugin>
-        <artifactId>maven-failsafe-plugin</artifactId>
-        <configuration>
-          <forkCount>1</forkCount>
-        </configuration>
-      </plugin>
       <plugin>
         <artifactId>maven-jar-plugin</artifactId>
         <configuration>

community/shell/src/test/java/org/neo4j/shell/AbstractShellIT.java

@@ -132,17 +132,29 @@ protected void makeServerRemotelyAvailable() throws RemoteException
     {
         if ( remotelyAvailableOnPort == null )
         {
-            remotelyAvailableOnPort = findFreePort();
-            shellServer.makeRemotelyAvailable( remotelyAvailableOnPort, SimpleAppServer.DEFAULT_NAME );
+            int attempts = 0;
+            int port = SimpleAppServer.DEFAULT_PORT;
+            do
+            {
+                try
+                {
+                    shellServer.makeRemotelyAvailable( port, SimpleAppServer.DEFAULT_NAME );
+                    remotelyAvailableOnPort = port;
+                }
+                catch ( Throwable error )
+                {
+                    port++;
+                    attempts++;
+                    if ( attempts == 100 )
+                    {
+                        throw new RuntimeException( "Not able to find free port more them 100 times.", error );
+                    }
+                }
+            }
+            while ( remotelyAvailableOnPort == null );
         }
     }
 
-    private int findFreePort()
-    {
-        // TODO
-        return SimpleAppServer.DEFAULT_PORT;
-    }
-
     protected void restartServer() throws Exception
     {
         shellServer.shutdown();