SGI MIPSpro fixes from Patrick Hartling

[SVN r16010]

src/exception.cpp

@@ -21,6 +21,7 @@
 #include <boost/config.hpp>
 #include <boost/filesystem/exception.hpp>
 
+#include <cstring> // SGI MIPSpro compilers need this
 #include <cerrno>
 #include <string>
 

src/path_posix_windows.cpp

@@ -40,6 +40,7 @@ namespace fs = boost::filesystem;
   namespace std { using ::strlen; }
 #endif
 
+#include <cstring>  // SGI MIPSpro compilers need this
 #include <vector>
 #include <cassert>