[boost] patch against boost threads library

From: Ulrich Eckhardt (uli_at_[hidden])
Date: 2005-03-02 17:03:10

Short notes:

 * thread_exception::message() is broken beyond repair, as it 
   returns a pointer to local storage (via std::string::c_str())
 * any program using it is broken, too.
 * it is unused by boost itself(!) which is why it can be removed
 * it is the only reason why a helper-function 'system_message()' 
   is needed, which can then be removed, too.
 * system_message() is the only reason several headers and a hack
   for strerror() were needed, which can then also be removed.
 * system_message() requires a char-based API on win32, which
   is not available under MS Windows CE, strerror() is also not
   available there, making two more reasons to remove it.

cheers

Uli