enhanced interactive role selection (trunk only)

[See cvs log for src/role.c for a much longer description.]

     When picking role, race, and so forth, new menu entries allow you to
pick any of the other items before the one currently being handled.  After
picking all four of race, role, gender, and alignment (or if you answered
'y' to "shall I pick for you?"), there is a followup prompt to confirm the
choices.  It's a menu which also provides a chance to rename the character.

     This has only been implemented in win/tty's player_selection(), with
some support code in the core that might be useful to other interfaces.
And so far, the chance to rename is only presented as a menu choice if
you've given an answer to "who are you?" prompt earlier during startup.
Also, ports that use pcmain.c aren't able to perform hero renaming yet.

include/flag.h

@@ -182,6 +182,8 @@ struct instance_flags {
 	boolean  menu_tab_sep;	/* Use tabs to separate option menu fields */
 	boolean  menu_requested; /* Flag for overloaded use of 'm' prefix
 				  * on some non-move commands */
+	boolean  renameallowed; /* can change hero name during role selection */
+	boolean  renameinprogress; /* we are changing hero name */
 	boolean  zerocomp;	/* write zero-compressed save files */
 	boolean  rlecomp;	/* run-length comp of levels when writing savefile */
 	uchar	 num_pad_mode;