Move src/lib/subs/empobj.c back to src/lib/common/

Commit 77e95bd7 (v4.3.12) moved it from its natural home because
obj_nameof() required stuff from subs/.  Now that obj_nameof() is
gone, move it back.

src/lib/common/empobj.c

@@ -0,0 +1,75 @@
+/*
+ *  Empire - A multi-player, client/server Internet based war game.
+ *  Copyright (C) 1986-2011, Dave Pare, Jeff Bailey, Thomas Ruschak,
+ *                Ken Stevens, Steve McClure, Markus Armbruster
+ *
+ *  Empire is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ *  ---
+ *
+ *  See files README, COPYING and CREDITS in the root of the source
+ *  tree for related information and legal notices.  It is expected
+ *  that future projects/authors will amend these files as needed.
+ *
+ *  ---
+ *
+ *  empobj.c: Common functions on struct empobj and
+ *            union empobj_storage
+ *
+ *  Known contributors to this file:
+ *     Ron Koenderink, 2006
+ *     Markus Armbruster, 2006-2008
+ */
+
+#include <config.h>
+
+#include "empobj.h"
+#include "file.h"
+#include "optlist.h"
+
+char *
+empobj_chr_name(struct empobj *gp)
+{
+    switch (gp->ef_type) {
+    case EF_LAND:
+	return lchr[(int)gp->type].l_name;
+    case EF_SHIP:
+	return mchr[(int)gp->type].m_name;
+    case EF_PLANE:
+	return plchr[(int)gp->type].pl_name;
+    case EF_NUKE:
+	return nchr[(int)gp->type].n_name;
+    case EF_SECTOR:
+	return dchr[(int)gp->type].d_name;
+    }
+    CANT_REACH();
+    return "The Beast";
+}
+
+int
+get_empobj_mob_max(int type)
+{
+    switch (type) {
+    case EF_SHIP:
+	return ship_mob_max;
+    case EF_LAND:
+	return land_mob_max;
+    case EF_PLANE:
+	return plane_mob_max;
+    case EF_SECTOR:
+	return sect_mob_max;
+    }
+    CANT_REACH();
+    return -1;
+}