This only happens if the user implements the separation oracle wrong.  In this
case I had the code setup to force the risk to zero but this just ends up
obscuring the fact that the user's separation oracle is incorrect.  So I'm
removing this check.  This should make debugging separation oracles a little
easier.

HTML pages are a little smaller.

--HG--
rename : examples/krr_classification_ex.cpp => examples/using_custom_kernels_ex.cpp

--HG--
rename : dlib/test/hash.cpp => dlib/test/kmeans.cpp

cross_validate_trainer_threaded() is executing.