fix cv::CommandLineParser.

It should handle bool value not only of "true" but also of "TRUE" and "True".

modules/core/include/opencv2/core/utility.hpp

@@ -808,7 +808,7 @@ public:
 
     This method returns the path to the executable from the command line (`argv[0]`).
 
-    For example, if the application has been started with such command:
+    For example, if the application has been started with such a command:
     @code{.sh}
     $ ./bin/my-executable
     @endcode
@@ -914,7 +914,7 @@ public:
     */
     void printMessage() const;
 
-    /** @brief Print list of errors occured
+    /** @brief Print list of errors occurred
 
     @sa check
     */