BugFix: round rooms drawn square if ensymbol-ed + missed bit of last commit

Forgot to include the place where the debug control introduced as a
sample/demo/illustration was actually used. Oops. 8-)

Also fixes a bug where rooms with a symbol (letter), even the invisible
space character, prevents round room symbols to be drawn on 2D maps.

Signed-off-by: Stephen Lyons <slysven@virginmedia.com>