This makes text boxes fade in and out pretty smoothly.
This requires that the textboxclass::setcol() be in Graphics::drawgui(),
so now it's moved there.
Text box fading is only really noticeable if you're playing in slowmode.
As a result of the previous commit, textboxclass::clear() is now unused.
textboxclass::firstcreate() was already useless. So remove both those
functions and initialize the values in the textboxclass constructor.
This removes the variables graphics.ntextbox, as well as removing
'active' from each text box object. Thus, all text boxes are really
real, and you don't have to check its 'active' variable.