implement more verbose "while helpless" messages

Signed-off-by: Steven Noonan <steven@uplinklabs.net>
impossible should tell people to save, not quit.
Pressing cmd key at direction prompt selects previously selected direction. (Patric Mueller, unnethack r844)
quiver_fired boolean option (Jukka Lahtinen)
add pickup_thrown option, to automatically pick up thrown items
Fix segfault when MD termcap not defined.