Run with java depend (don't require java in path).

Index: bin/kawa.c
--- bin/kawa.c.orig
+++ bin/kawa.c
@@ -517,7 +517,7 @@ main(int argc, char** argv)
   out_argv[out_argc++] = get_command (argv[0]);
 #else
   putenv (get_classpath(argv[0]));
-  out_argv[out_argc++] = "java";
+  out_argv[out_argc++] = "${JAVA_HOME}/bin/java";
 #endif
 
   /* Calculate and set the kawa.command.line property. */
