HONEYCOMB-67 Introduce exception handling into JVPP

Send calls throws VppInvocationException on failure
Failed requests (negative retval) reported over onError callback interface method
Removed retval attributes from dto/xxxReply.java calls

Change-Id: Ibd4e90c320d080e02d75b4bd056a7b11c8e37aa7
Signed-off-by: Tibor Sirovatka <tsirovat@cisco.com>
diff --git a/vpp-api/java/jvpp/gen/util.py b/vpp-api/java/jvpp/gen/util.py
index f951bf8..072c9d5 100644
--- a/vpp-api/java/jvpp/gen/util.py
+++ b/vpp-api/java/jvpp/gen/util.py
@@ -45,6 +45,9 @@
 def is_details(name):
     return name.lower().endswith(reply_suffixes[1]) or name.lower().endswith(reply_suffixes[2])
 
+def is_retval_field(name):
+    return name == 'retval'
+
 dump_suffix = "dump"