Make private constructors package-private because code-analyzers

complain about it because they cannot see that JNI is creating the
classes.

src/main/java/de/ailis/usb4java/libusb/Device.java

@@ -40,10 +40,10 @@ public final class Device
     private long pointer;
 
     /**
-     * Private constructor to prevent manual instantiation. Devices are
+     * Package-private constructor to prevent manual instantiation. Devices are
      * always created by JNI.
      */
-    private Device()
+    Device()
     {
         // Empty
     }

src/main/java/de/ailis/usb4java/libusb/EndpointDescriptor.java

@@ -34,10 +34,10 @@ public final class EndpointDescriptor implements UsbEndpointDescriptor
     private long pointer;
 
     /**
-     * Private constructor to prevent manual instantiation. Endpoint 
-     * descriptors area always created by JNI.
+     * Package-private constructor to prevent manual instantiation. Endpoint 
+     * descriptors are always created by JNI.
      */
-    private EndpointDescriptor()
+    EndpointDescriptor()
     {
         // Empty
     }

src/main/java/de/ailis/usb4java/libusb/Interface.java

@@ -24,10 +24,10 @@ public final class Interface
     private long pointer;
 
     /**
-     * Private constructor to prevent manual instantiation. Interfaces 
-     * area always created by JNI.
+     * Package-private constructor to prevent manual instantiation. Interfaces 
+     * are always created by JNI.
      */
-    private Interface()
+    Interface()
     {
         // Empty
     }

src/main/java/de/ailis/usb4java/libusb/InterfaceDescriptor.java

@@ -34,10 +34,10 @@ public final class InterfaceDescriptor implements UsbInterfaceDescriptor
     private long pointer;
 
     /**
-     * Private constructor to prevent manual instantiation. Interface 
-     * descriptors area always created by JNI.
+     * Package-private constructor to prevent manual instantiation. Interface 
+     * descriptors are always created by JNI.
      */
-    private InterfaceDescriptor()
+    InterfaceDescriptor()
     {
         // Empty
     }

src/main/java/de/ailis/usb4java/libusb/Version.java

@@ -26,10 +26,10 @@ public final class Version implements Comparable<Version>
     private long pointer;
     
     /**
-     * Private constructor to prevent manual instantiation. An instance
+     * Package-private constructor to prevent manual instantiation. An instance
      * is only returned by the JNI method {@link LibUSB#getVersion()}.
      */
-    private Version()
+    Version()
     {
         // Empty
     }