Fix object visuals dumping bug reported at http://angband.oook.cz/forum/showthread.php?t=5864
(cherry picked from commit 545691a9fc053a72a43108985bd68a2a113a3095)
* constify borg_wield_slot() [note: this should just use the normal wield_slot()]
* refactor the borg ID routines:
  - take into account the fact the game hasn't had weak pseudo ID for four years
  - clean up a lot of code that has not been kept tidy over time
* (hopefully) fix ID routines getting confused about which inven/equip screen the game is on
(cherry picked from commit 4589bc2c1edd7a13b3744540b4efb424e81e5554)
Fix instances of msg(NULL) -> message_flush().  The former caused crashes in vstrnfmt.
(cherry picked from commit 85fd554043d3a816e20faa52beefa1d279d45805)
Be more helpful when reminding the user where their borg.txt file should be.
(cherry picked from commit b4a0e7eed5d829f426161d49cd2cd98ec8b74168)
Fix rubble digging and refactor relevent code a bit
(cherry picked from commit 2d1e1e00b520adefd2e42864df8f8a8a238de457)
Get the borg help working (Ctrl-Z ?).
(cherry picked from commit 34076044187584dc9668c21ff6d09b581cbaee78)
The borg fails bigtime when lazy movement is turned on so the borg will now turn it off when it starts.
(cherry picked from commit b79477ea4da3b11258109a8606ed216067ac24fb)