Fix crashes in swig_connect_director during director class construction.

Occurs when using the director class from multiple threads - a race condition
initialising block scope static variables.

Block scope static variables are guaranteed to be thread safe in C++11,
so the fix is guaranteed when using C++11. However, most modern compilers
also fix it when using C++03/C++98.

Closes #1862

Lib/java/director.swg

@@ -215,6 +215,15 @@ namespace Swig {
       }
     };
 
+    struct SwigDirectorMethod {
+      const char *name;
+      const char *desc;
+      jmethodID methid;
+      SwigDirectorMethod(JNIEnv *jenv, jclass baseclass, const char *name, const char *desc) : name(name), desc(desc) {
+        methid = jenv->GetMethodID(baseclass, name, desc);
+      }
+    };
+
     /* Java object wrapper */
     JObjectWrapper swig_self_;
 
@@ -238,6 +247,11 @@ namespace Swig {
       }
     }
 
+    jclass swig_new_global_ref(JNIEnv *jenv, const char *classname) {
+      jclass clz = jenv->FindClass(classname);
+      return clz ? (jclass)jenv->NewGlobalRef(clz) : 0;
+    }
+
   public:
     Director(JNIEnv *jenv) : swig_jvm_((JavaVM *) NULL), swig_self_() {
       /* Acquire the Java VM pointer */