VPP-530: adapt jvpp generation for VPP API splitting

Now jvpp uses *.json instead of *.py api representation.
Multiple *.json files are supported.

Change-Id: I89fa556c7d2a35d42833f2faaa28398ebd2ed012
Signed-off-by: Marek Gradzki <mgradzki@cisco.com>

vpp-api/java/jvpp-core/jvpp_core.c

@@ -38,7 +38,7 @@
 
 // TODO: generate jvpp_plugin_name.c files (or at least reuse plugin's main structure)
 typedef struct {
-    /* Base message index for the nsh plugin */
+    /* Base message index for the jvpp-core plugin */
     u16 msg_id_base;
 
     /* Pointer to shared memory queue */