remove unused macros defining corner positions

As pointed by gcc, the 4 constant the define the corner positions are not
used anywhere in the code, and it looks like it has always been like this.
As it is a cost for maintainability, get rid of them.

Signed-off-by: Christophe CURIS <christophe.curis@free.fr>

src/balloon.c

@@ -72,11 +72,6 @@ typedef struct _WBalloon {
 #define LEFT	0
 #define RIGHT	2
 
-#define TLEFT (TOP|LEFT)
-#define TRIGHT (TOP|RIGHT)
-#define BLEFT (BOTTOM|LEFT)
-#define BRIGHT (BOTTOM|RIGHT)
-
 static int countLines(const char *text)
 {
 	const char *p = text;