our policy is that we only use boost if necessary, i.e., if the oldest
supported compiler does not support a given feature but boost
does. since we recently switched to GCC 4.4 or newer, std::shared_ptr
is available unconditionally.
Disabled by default, this statement attempted to pass a std::istream to
function std::fclose() which is meaningless and should not be enabled at
any time--even for a MATLAB-related build.