Builds w/ TR1-capable compiler have some clashes with Boost

Trying a build with Visual Studio 2010 tripped a few places where the new TR1 classes/algorithms clash with the Boost equivalents from which they were inspired. Although I saw this with VS2010, it's not a Windows/VS-specific problem - that's just where it was seen first.

Ones I've seen...

cpp/src/tests/SessionState.cpp use of ref, bind
cpp/src/tests/perftest.cpp use of bind

This could be remedied by removing the "using boost" statements (and/or "using std" statements). Also possible is a config check for presence of the TR1 stuff and use the TR1 if available, else Boost.