Update license information for Boost backported code.

src/mlpack/core/boost_backport/LICENSE.txt

@@ -0,0 +1,23 @@
+Boost Software License - Version 1.0 - August 17th, 2003
+
+Permission is hereby granted, free of charge, to any person or organization
+obtaining a copy of the software and accompanying documentation covered by
+this license (the "Software") to use, reproduce, display, distribute,
+execute, and transmit the Software, and to prepare derivative works of the
+Software, and to permit third-parties to whom the Software is furnished to
+do so, all subject to the following:
+
+The copyright notices in the Software and this entire statement, including
+the above license grant, this restriction and the following disclaimer,
+must be included in all copies of the Software, in whole or in part, and
+all derivative works of the Software, unless such copies or derivative
+works are solely in the form of machine-executable object code generated by
+a source language processor.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
+SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
+FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
+ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+DEALINGS IN THE SOFTWARE.

src/mlpack/core/boost_backport/README.md

@@ -1,3 +1,12 @@
 The files in this directory are taken from Boost 1.56.0 in order to backport
 serialization support for unordered_map.  Therefore these files are licensed
-under the Boost Software License.
+under the Boost Software License, available in LICENSE.txt in this directory.
+
+If you want a copy of mlpack without a dependence on the Boost Software License,
+then you will need to
+
+ * remove this entire directory
+ * remove the line "boost_backport" from src/mlpack/core/CMakeLists.txt
+ * change the line "find_package(Boost x.yy" in the root CMakeLists.txt so that
+   x is 1 and yy is at least 56.  (That is, make mlpack require Boost 1.56 or
+   newer).

src/mlpack/core/boost_backport/unordered_collections_load_imp.hpp

@@ -1,3 +1,6 @@
+// Distributed under the Boost Software License, Version 1.0.
+//    (See accompanying file LICENSE.txt or copy at
+//          http://www.boost.org/LICENSE_1_0.txt)
 #ifndef BOOST_SERIALIZATION_UNORDERED_COLLECTIONS_LOAD_IMP_HPP
 #define BOOST_SERIALIZATION_UNORDERED_COLLECTIONS_LOAD_IMP_HPP
 

src/mlpack/core/boost_backport/unordered_collections_save_imp.hpp

@@ -1,3 +1,6 @@
+// Distributed under the Boost Software License, Version 1.0.
+//    (See accompanying file LICENSE.txt or copy at
+//          http://www.boost.org/LICENSE_1_0.txt)
 #ifndef BOOST_SERIALIZATION_UNORDERED_COLLECTIONS_SAVE_IMP_HPP
 #define BOOST_SERIALIZATION_UNORDERED_COLLECTIONS_SAVE_IMP_HPP
 

src/mlpack/core/boost_backport/unordered_map.hpp

@@ -1,4 +1,7 @@
-#ifndef  BOOST_SERIALIZATION_UNORDERED_MAP_HPP
+// Distributed under the Boost Software License, Version 1.0.
+//    (See accompanying file LICENSE.txt or copy at
+//          http://www.boost.org/LICENSE_1_0.txt)
+#ifndef BOOST_SERIALIZATION_UNORDERED_MAP_HPP
 #define BOOST_SERIALIZATION_UNORDERED_MAP_HPP
 
 // MS compatible compilers support #pragma once