Added examples in /example folder (contain snippets for Quickbook), and updates to add typedef static_gcd_t for common factor

example/integer_log2_example.cpp

@@ -0,0 +1,41 @@
+// boost integer_log2_example.cpp 
+
+// Copyright Paul A. Bristow 2015
+// Use, modification and distribution are subject to the
+// Boost Software License, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt
+// or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// Caution: this file contains Quickbook markup as well as code
+// and comments, don't change any of the special comment markups!
+
+//[integer_log2_example_0
+#include <boost/integer/static_log2.hpp> // For boost::static_log2
+//] [/integer_log2s_example_0]
+#include <iostream> 
+#include <limits>  // for numeric_limits min and max.
+
+//[integer_log2_example_
+//] [/integer_log2s_example_]
+
+int main()
+{
+//[integer_log2_example_1
+  int n = boost::static_log2<256>::value;
+//] [/integer_log2_example_1]
+
+  std::cout << n << std::endl; // 8
+
+  //[integer_log2_example_2
+  int n2 = boost::static_log2<65536>::value;
+//] [/integer_log2_example_2]
+
+  std::cout << n2 << std::endl; // 16
+
+} // int main
+
+/*
+//[integer_log2_example_output
+8
+//] [/integer_log2_example_output]
+*/