Change call `tparam' so that it does not depend on a feature only

Change call `tparam' so that it does not depend on a feature only
available in GNU `tparam'.  This is important on GNU/Linux because it
allows us to statically link "ncurses".

This has the added benefit that it allows the "ncurses" stuff to work
correctly.  Previously, when using "ncurses", the screen was scrambled
so badly that it couldn't be used.  This appears to be a consequence
of the combination of GNU `tparam' with "ncurses".