Blank module and first draft of solver API.

At this point we have a skeleton of a new module (optim) which can
barely compile properly (unlike previous commit). Besides, there is a
first draft of solver and lpsolver (linear optimization solver) in this
commit.

modules/optim/test/test_precomp.hpp

@@ -1,17 +0,0 @@
-#ifdef __GNUC__
-#  pragma GCC diagnostic ignored "-Wmissing-declarations"
-#  if defined __clang__ || defined __APPLE__
-#    pragma GCC diagnostic ignored "-Wmissing-prototypes"
-#    pragma GCC diagnostic ignored "-Wextra"
-#  endif
-#endif
-
-#ifndef __OPENCV_TEST_PRECOMP_HPP__
-#define __OPENCV_TEST_PRECOMP_HPP__
-
-#include <iostream>
-#include "opencv2/ts.hpp"
-#include "opencv2/photo.hpp"
-#include "opencv2/highgui.hpp"
-
-#endif