Chronicle of major events, and livelog

Log game events, such as entering a new dungeon level, breaking
a conduct, or killing a unique monster, in a new "Major events"
chronicle. The entries record the turn when the event happened.
The log can be viewed with #chronicle -command, and the entries
also show up in the end-of-game dump, if that is available.

This feature is on by default, but can be disabled by
defining NO_CHRONICLE compile-time option.

This also contains "live logging", writing the events as they
happen into a single livelog-file. This is mostly useful for
public servers. The livelog is off by default, and must be
compiled in with LIVELOG, and then turned on in sysconf.

Mostly this a version of livelogging from the Hardfought server,
with some changes.

src/fountain.c

@@ -392,6 +392,7 @@ dipfountain(register struct obj *obj)
                 obj->spe--;
             obj->oerodeproof = FALSE;
             exercise(A_WIS, FALSE);
+            livelog_printf(LL_ARTIFACT, "was denied Excalibur! The Lady of the Lake has deemed %s unworthy", uhim());
         } else {
             /* The lady of the lake acts! - Eric Backus */
             /* Be *REAL* nice */
@@ -404,6 +405,7 @@ dipfountain(register struct obj *obj)
             obj->oeroded = obj->oeroded2 = 0;
             obj->oerodeproof = TRUE;
             exercise(A_WIS, TRUE);
+            livelog_printf(LL_ARTIFACT, "was given Excalibur");
         }
         update_inventory();
         levl[u.ux][u.uy].typ = ROOM, levl[u.ux][u.uy].flags = 0;