pager: config variable pager.color

enable/disable colored output when the pager is in use

Signed-off-by: Matthias Lederhofer <matled@gmx.net>
Signed-off-by: Junio C Hamano <junkio@cox.net>

cache.h

@@ -386,6 +386,7 @@ extern int receive_keep_pack(int fd[2], const char *me, int quiet, int);
 /* pager.c */
 extern void setup_pager(void);
 extern int pager_in_use;
+extern int pager_use_color;
 
 /* base85 */
 int decode_85(char *dst, char *line, int linelen);