When text gets very small, the FTGL font renderer may cause an OpenGL error to...

When text gets very small, the FTGL font renderer may cause an OpenGL error to occur many times and potentially, fill up a user's log file.  So, immediately after the glTexSubImage2D function call that causes, the error, simply call glGetError() to reset the error status and prevent printing of an error message during a later test for an OpenGL error.