X11 dynamic map mode selection

X11 dynamic map mode selection
Prompted by a question from Pat a long time back, this change finally allows
tiles or text map mode to be chosen dynamically at runtime (using the
"tiled_map" option) rather than having to pick it via an X resource and
keep your selection until you exit. This brings map mode selection up to a
level similar to most other graphical window ports.
In addition, the map mode automatically switches to text on the Rogue
level, also like other graphical window ports.
The default mode for the X11 binary is now tiles, once again, like most (all?)
other graphical window ports.
The patch also removes some dead X11 code that is unlikely to be useful again.