You can make the warnings go away. How is stupidly simple, and has been documented many times.
myGLCD.print((char *)"Fark: ",5,40);
Cast the const char * to a char *, which is what the (poorly implemented) function expects.
I say poorly-implemented, because the print() method should NOT be modifying the pointer, and should assure that it wont by making the argument const. But it wasn't properly written, so you have to work around it.