Added ostream-like cv::putText helper function

This commit brings an ostream-like text rendering on the cv::Mat.
Unlike existing function, a new putText funtion allows to use operator << to print
text on cv::Mat and supports newline characters. You can see the
demonstration of the new cv::putText in drawing.cpp sample.

The proposed request allows to print text on the images in the following way:

	putText(image2, cv::Point(100,100), CV_FONT_HERSHEY_COMPLEX, 1, Scalar(i, i, 255))
		<< "cv::putText() Demo!" << std::endl 
		<< "cv::putText(...) << \"Hello\\nWorld\";" << std::endl 
		<< "You can use std::endl" << std::endl 
		<< "or even\\n symbol\nto format text" << std::endl
		<< "And we support formatters:\n"
		<< "std::setprecision(5)" << std::setprecision(5) << CV_PI << std::endl
		<< "std::scientific " << std::scientific << CV_PI << std::endl
		<< "So you can use cv::putText like regular std::cout!";
	
The result of the rendering will be:
![putTextOstream](https://f.cloud.github.com/assets/532320/82343/09a86960-63a1-11e2-8665-eee31c1a2581.png)