Created new console output method: sbbs_t::backfill():

it displays a string of text and fills the background color up to the
specified percentage fo the string length. I will be using it for displaying
poll results, but it could possibly be used for progress displays and such.
The colors used are configured via the "backfill" and "unfill" attributes in
ctrl/attr.cfg.

src/sbbs3/con_out.cpp

@@ -621,4 +621,23 @@ bool sbbs_t::msgabort()
 	return(false);
 }
 
+int sbbs_t::backfill(const char* str, float pct)
+{
+	uint8_t	atr;
+	int len;
+
+	if(!term_supports(ANSI))
+		return bputs(str);
 
+	len = strlen(str);
+	for(int i=0; i<len; i++) {
+		if(((float)i / len)*100.0 <= pct)
+			atr = cfg.color[clr_backfill];
+		else
+			atr = cfg.color[clr_unfill];
+		if(curatr != atr) attr(atr);
+		outchar(str[i]);
+	}
+	attr(LIGHTGRAY);
+	return len;
+}

src/sbbs3/sbbs.h

@@ -674,6 +674,7 @@ public:
 	void	cursor_left(int count=1);
 	void	cursor_right(int count=1);
 	long	term_supports(long cmp_flags=0);
+	int		backfill(const char* str, float pct);
 
 	/* getstr.cpp */
 	size_t	getstr_offset;