Hew to upstream's declarations-before-code style

Also, the first commit neglected to say "Addresses #523", so here's that.

Author: jcflack

pljava-so/src/main/c/Invocation.c

@@ -230,9 +230,9 @@ void Invocation_popInvocation(bool wasException)
 	{
 		jthrowable ex = (jthrowable)JNI_getStaticObjectField(
 			s_Invocation_class, s_Invocation_s_unhandled);
+		bool already_hit = Exception_isPGUnhandled(ex);
 		JNI_setStaticObjectField(
 			s_Invocation_class, s_Invocation_s_unhandled, NULL);
-		bool already_hit = Exception_isPGUnhandled(ex);
 
 		JNI_exceptionStacktraceAtLevel(ex,
 			wasException ? DEBUG2 : already_hit ? WARNING : DEBUG1);