Symbol set changes...
curses:
S_tree (use plus-or-minus sign instead of accidental horizontal line);
S_bars (switch from default '#' to not-equals sign);
DECgraphics:
S_altar (switch from default '_' to 'pi');
S_bars (switch from 'pi' to not-equals sign);
DECgraphics_2: get rid of this commented out set since its contents are
now folded into DECgraphics.
(The IBMgraphics one is just whitespace; delete a <space> that precedes
a <tab>.)
7efdec7f5e