Revert "add new version of CommandLineParser. add empty docs"

This reverts commit 54a202b3d5.

Conflicts:
	modules/core/doc/command_line_parser.rst
	modules/core/include/opencv2/core/core.hpp
	modules/core/src/cmdparser.cpp
	modules/gpu/perf/main.cpp
	modules/gpu/test/main.cpp
	modules/ts/src/ts_perf.cpp

samples/cpp/opencv_version.cpp

@@ -3,23 +3,19 @@
 
 const char* keys = 
 {
-    "{ b build | | print complete build info }"
-    "{ h help  | | print this help           }"
+    "{ b |build |false | print complete build info }"
+    "{ h |help  |false | print this help           }"
 };
 
 int main(int argc, const char* argv[])
 {
     cv::CommandLineParser parser(argc, argv, keys);
 
-    if (parser.has("help"))
+    if (parser.get<bool>("help"))
     {
-        parser.printMessage();
+        parser.printParams();
     }
-    else if (!parser.check())
-    {
-        parser.printErrors();
-    }
-    else if (parser.has("build"))
+    else if (parser.get<bool>("build"))
     {
         std::cout << cv::getBuildInformation() << std::endl;
     }
@@ -29,4 +25,4 @@ int main(int argc, const char* argv[])
     }
 
     return 0;
-}
+}