Apply a wielded polearm with fire-command

Wield a polearm and use 'f'ire to automatically hit with it,
if there's a single valid target.
With fireassist-option, will swapweapon to a polearm.
This only applies if quiver is empty and autoquiver is off.

doc/fixes37.0

@@ -725,6 +725,7 @@ apply runmode delay to multiturn actions, not just running
 if a giant carrying a boulder was on ice that melted, it could be killed
 	twice, first by drowning, then by boulder filling the resulting pool
 	when it dropped inventory before being removed from the map
+allow fire-command to automatically use a polearm, if wielding it
 
 
 Fixes to 3.7.0-x Problems that Were Exposed Via git Repository