Fix curses library detection. A custom autoconf macro searched for the curses library, and provided an option to use ncurses instead of a (presumably deficient) curses implementation. Unfortunately, some of the Makefiles ignored the search's results. Now that this is fixed, building against pdcurses should be easier too.

[Desktop Entry]
Encoding=UTF-8
Name=Rogue
GenericName=Rogue
Comment=The original curses-based adventure game
Exec=rogue
Icon=rogue.png
Terminal=true
Type=Application
Categories=Game;RolePlaying;
Version=1.0