Split SET_UID option out into SETGID (for multiuser installs) and UNIX.  UNIX also includes OS X.
Make -d work better (thanks to lastquestion).
Merge pull request #219 from takkaria/dopt

Make the CLI option -d useful (update to pullreq #185)
Fix up previous SET_UID -> UNIX change.
Unbreak roguelike keys ('X' is back to being 'swap weapon' again)
- Add a list savefiles function to save.c
- Add function to transition from old savefile name format to new format
Merge pull request #220 from takkaria/list-saves

Savefile location fix on non-setgid UNIXes and 'list savefiles' feature for our dear comandline users
Refactor savefile loading framework into multipe shorter functions.
Add a rd_null() function for savefile blocks which aren't used anymore instead of duplicating that acros multiple functions.
Add description block in the savefile which is a one-line summary of the player
Remove ancient savefile loaders.
Add savefile_get_description()