Improve write function

[staxfur]

As introduced in #64 and already implemented in #68. I have removed the write funktion from the library, which simply is an alias for std::cout. @certik argument to provide a simple function to hide the "cmplicated" stuff, I think, that std::cout << s << std::flush; is a well known thing in C++ and make the code more clear without hiding the actuall code. But as it's just an optional wrapper, i would understand to just keep it for those, who want a really simple fucntion.

[certik]

I think it's probably fine, but let me think about this one a bit. I don't know how common is to know that you have to call std::flush at the end, otherwise it sometimes does not work.

[staxfur]

Yeah, std::flush forces 'flushing' the iostream, so basically it tells the console to draw out everything that is pending. If I get it right, the terminal or the iostream is not writing to the console imideately, but at the end of the section (the function for example).

[staxfur]

Small thought:
Is the write() function needed, if the terminal should be used with the Window class in the end? Otherwise you are probably right about providing the write() function. I would still change everything to use that function. There are some std::cout << s << std::flush inside of the code that are not using write().

[certik]

Yes, I noticed that. I think we can probably take the write function out of the class and just have a global function in the term namespace.

I would lean towards keeping the function, at the very least, it is shorter to write

term::write("x");

than

std::cout << x << std::flush;