- add a "-d" option, to specify the display cwm should be started on

- adjust argc/argv by optind
- add an ENVIRONMENT section to the manpage

ok matthieu@ ray@

calmwm.h

@@ -285,7 +285,7 @@ struct mwm_hints {
 int input_keycodetrans(KeyCode, u_int, enum ctltype *, char *, int);
 
 int   x_errorhandler(Display *, XErrorEvent *);
-void  x_setup(void);
+void  x_setup(char *display_name);
 char *x_screenname(int);
 void  x_loop(void);
 int   x_setupscreen(struct screen_ctx *, u_int);