Dev/kwiver integration

On Mon, Aug 25, 2014 at 10:07:08 -0700, linus-sherrill wrote:
> The only constructor for this exception is bad_configuration_cast(char const*
> reason) SPROKIT_NOTHROW; It is possible that this is not the best exception to
> throw here. An alternative is to use the "bad_configuration_cast_exception",
> but there is no "key" available at this point.

Oops, should have seen that it didn't end with '_exception' and
therefore wasn't a user-seen exception. Above, it is caught and the key
information is added. The intermediate storage for the string is a
std::string (m_what), so this is fine.