svm_c_linear_trainer and svm_c_ekm_trainer objects.  However,
there was a bug which made them only ever do at most 16 iterations,
which is too few to solve many problems.  This has been fixed.

Now if you don't define it you get a reasonable default behavior
rather than a compiler error.

--HG--
rename : examples/svm_ex.cpp => examples/sequence_labeler_ex.cpp

and cleaned up a few other related things.

labeling using dlib's structural SVM implementation.

to the cross_validate_multiclass_trainer() routine.  Not it will
throw an exception if the number of folds is too big rather than
just producing a confusing result.