documentation update

Incorporate the diff from entrez describing the travel_debug wizard
mode option and removing obsolete M prefix from the Guidebook.  That
missed a reference to it in the description of '_'.

I put M back in case someone who has used it with earlier versions
tries to use it and gets a no-such-command complaint so goes looking
for it.

Also, make the mention of ^X at the end of the discussion of status
stand out a bit.  The indentation of its paragraph made it line up
with the preceding text instead of making it be distinct from that.

The TeX changes are untested and given the amount of punctuation
characters used, it will be surprising if they all have been quoted
properly.

dat/opthelp

@@ -134,7 +134,7 @@ tiled_map      show map as tiles, forces ascii_map Off; Qt, X11
 Boolean options available when running in debug mode (aka wizard mode):
 menu_tab_sep   menu formatting--do not touch
 monpolycontrol have player choose shape-changing monsters' new shapes
-travel_debug   not implemented?
+travel_debug   show state of travel pathfindinging algorithm on the map
 wizweight      include item weights in inventory display
 
 Any Boolean option can be set to True by including it among options being