title: boost ipc warning - on inclusion of managed_shared_memory
body: <p>Hi I get the following warnings </p>
  
  <pre><code>g++ -std=c++0x -Wall -c -I/usr/local/boost_1_53_0 -I/home/aditya/CodeBase/includes      MAIN.cpp 
  In file included from /usr/local/boost_1_53_0/boost/interprocess/detail/managed_open_or_create_impl.hpp:15:0,
               from /usr/local/boost_1_53_0/boost/interprocess /managed_shared_memory.hpp:22,
               from MAIN.cpp:22:
  /usr/local/boost_1_53_0/boost/interprocess/detail/os_thread_functions.hpp: In function  ‘void boost::interprocess::ipcdetail::thread_sleep(unsigned int)’:
  /usr/local/boost_1_53_0/boost/interprocess/detail/os_thread_functions.hpp:169:65: warning: narrowing conversion of ‘(ms / 1000u)’ from ‘unsigned int’ to ‘__time_t {aka long int}’ inside { } [-Wnarrowing]
  /usr/local/boost_1_53_0/boost/interprocess/detail/os_thread_functions.hpp:169:65: warning: narrowing conversion of ‘((ms % 1000u) * 1000000u)’ from ‘unsigned int’ to ‘long int’ inside { } [-Wnarrowing]
  </code></pre>
  
  <p>on compiling the following program</p>
  
  <pre><code>#include &lt;iostream&gt;
  #include &lt;memory&gt;
  #include &lt;boost/thread.hpp&gt;
  #include &lt;boost/managed_shared_memory.hpp&gt;
  
  int main(){
  
     return 0;
  }
  </code></pre>
  
  <p>I'm using gcc 4.7 on an ubuntu 12.04</p>